Publications by Department of Nonlinear Optics

Departments of ISQI | Publications of ISQI

60 entries « ‹ 1 of 2 › »

2024
60.	Deng-Gao Lai, C.-H. Wang, B.-P. Hou, Adam Miranowicz, Franco Nori Exceptional refrigeration of motions beyond their mass and temperature limitations Optica, 11 (4), pp. 485-491, 2024. Abstract \| Links \| BibTeX @article{Lai2024, title = {Exceptional refrigeration of motions beyond their mass and temperature limitations}, author = {Deng-Gao Lai and C.-H. Wang and B.-P. Hou and Adam Miranowicz and Franco Nori}, url = {https://opg.optica.org/optica/abstract.cfm?URI=optica-11-4-485}, doi = {10.1364/OPTICA.495199}, year = {2024}, date = {2024-04-08}, journal = {Optica}, volume = {11}, number = {4}, pages = {485-491}, abstract = {Coaxing vibrations in the regimes of both large mass and high temperature into their motional quantum ground states is extremely challenging, because it requires an ultra-high optical power, which introduces extraneous excessive heating and intricate instabilities. Here we propose how to overcome these obstacles and cool vibrational networks by simply harnessing the power of an exceptional point (EP) induced in parity-time symmetric structures; and we reveal its exceptional cooling properties otherwise unachievable in conventional devices. In stark contrast to standard-cooling protocols, a three orders-of-magnitude amplification in net cooling rates arises from the EP-cooling mechanism, without which it vanishes. Remarkably, our EP cooling is nearly immune to both resonator mass and environmental temperature, and this overthrows the consensus that poor intrinsic factors and rugged extrinsic environment suppress cooling channels. Our study offers the possibility of isolating and engineering motional properties of large-mass and high-temperature objects for various applications in optical and acoustic sensing, gravimetry, and inertial navigation.}, }, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Coaxing vibrations in the regimes of both large mass and high temperature into their motional quantum ground states is extremely challenging, because it requires an ultra-high optical power, which introduces extraneous excessive heating and intricate instabilities. Here we propose how to overcome these obstacles and cool vibrational networks by simply harnessing the power of an exceptional point (EP) induced in parity-time symmetric structures; and we reveal its exceptional cooling properties otherwise unachievable in conventional devices. In stark contrast to standard-cooling protocols, a three orders-of-magnitude amplification in net cooling rates arises from the EP-cooling mechanism, without which it vanishes. Remarkably, our EP cooling is nearly immune to both resonator mass and environmental temperature, and this overthrows the consensus that poor intrinsic factors and rugged extrinsic environment suppress cooling channels. Our study offers the possibility of isolating and engineering motional properties of large-mass and high-temperature objects for various applications in optical and acoustic sensing, gravimetry, and inertial navigation.}, Close https://opg.optica.org/optica/abstract.cfm?URI=optica-11-4-485 doi:10.1364/OPTICA.495199 Close
59.	Chia-Yi Ju, Adam Miranowicz, Yueh-Nan Chen, Guang-Yin Chen, Franco Nori Emergent parallel transport and curvature in Hermitian and non-Hermitian quantum mechanics Quantum, 8 , pp. 1277, 2024. Abstract \| Links \| BibTeX @article{Ju2024, title = {Emergent parallel transport and curvature in Hermitian and non-Hermitian quantum mechanics}, author = {Chia-Yi Ju and Adam Miranowicz and Yueh-Nan Chen and Guang-Yin Chen and Franco Nori}, url = {https://quantum-journal.org/papers/q-2024-03-13-1277/}, doi = {10.22331/q-2024-03-13-1277}, year = {2024}, date = {2024-03-13}, journal = {Quantum}, volume = {8}, pages = {1277}, abstract = {Studies have shown that the Hilbert spaces of non-Hermitian systems require nontrivial metrics. Here, we demonstrate how evolution dimensions, in addition to time, can emerge naturally from a geometric formalism. Specifically, in this formalism, Hamiltonians can be interpreted as a Christoffel symbol-like operators, and the Schroedinger equation as a parallel transport in this formalism. We then derive the evolution equations for the states and metrics along the emergent dimensions and find that the curvature of the Hilbert space bundle for any given closed system is locally flat. Finally, we show that the fidelity susceptibilities and the Berry curvatures of states are related to these emergent parallel transports.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Studies have shown that the Hilbert spaces of non-Hermitian systems require nontrivial metrics. Here, we demonstrate how evolution dimensions, in addition to time, can emerge naturally from a geometric formalism. Specifically, in this formalism, Hamiltonians can be interpreted as a Christoffel symbol-like operators, and the Schroedinger equation as a parallel transport in this formalism. We then derive the evolution equations for the states and metrics along the emergent dimensions and find that the curvature of the Hilbert space bundle for any given closed system is locally flat. Finally, we show that the fidelity susceptibilities and the Berry curvatures of states are related to these emergent parallel transports. Close https://quantum-journal.org/papers/q-2024-03-13-1277/ doi:10.22331/q-2024-03-13-1277 Close
58.	Arnab Laha, Adam Miranowicz, R. K. Varshney, Somnath Ghosh Correlated nonreciprocity around conjugate exceptional points Phys. Rev. A, 109 , pp. 033511, 2024. Abstract \| Links \| BibTeX @article{Laha2024, title = {Correlated nonreciprocity around conjugate exceptional points}, author = {Arnab Laha and Adam Miranowicz and R. K. Varshney and Somnath Ghosh}, url = {https://link.aps.org/doi/10.1103/PhysRevA.109.033511}, doi = {10.1103/PhysRevA.109.033511}, year = {2024}, date = {2024-03-08}, journal = {Phys. Rev. A}, volume = {109}, pages = {033511}, abstract = {The occurrence of exceptional points (EPs) is a fascinating non-Hermitian feature of open systems. A level-repulsion phenomenon between two complex states of an open system can be realized by positioning an EP and its time-reversal ( T ) conjugate pair in the underlying parameter space. Here, we report interesting nonreciprocal responses of such two conjugate EPs by using a dual-mode planar waveguide system having two T -symmetric active variants concerning the transverse gain-loss profiles. We specifically reveal an all-optical scheme to achieve correlative nonreciprocal light dynamics by using the reverse chirality of two dynamically encircled conjugate EPs in the presence of local nonlinearity. A specific nonreciprocal correlation between two designed T -symmetric waveguide variants is established in terms of their unidirectional transfer of light with a precise selection of modes. Here, the unconventional reverse chiral properties of two conjugate EPs allow the nonreciprocal transmission of two selective modes in the opposite directions of the underlying waveguide variants. An explicit dependence of the nonlinearity level on a significant enhancement of the nonreciprocity in terms of an isolation ratio is explored by investigating the effects of both local Kerr-type and saturable nonlinearities (considered separately). The physical insights and implications of harnessing the features of conjugate EPs in nonlinear optical systems can enable the growth and development of a versatile platform for building nonreciprocal components and devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The occurrence of exceptional points (EPs) is a fascinating non-Hermitian feature of open systems. A level-repulsion phenomenon between two complex states of an open system can be realized by positioning an EP and its time-reversal ( T ) conjugate pair in the underlying parameter space. Here, we report interesting nonreciprocal responses of such two conjugate EPs by using a dual-mode planar waveguide system having two T -symmetric active variants concerning the transverse gain-loss profiles. We specifically reveal an all-optical scheme to achieve correlative nonreciprocal light dynamics by using the reverse chirality of two dynamically encircled conjugate EPs in the presence of local nonlinearity. A specific nonreciprocal correlation between two designed T -symmetric waveguide variants is established in terms of their unidirectional transfer of light with a precise selection of modes. Here, the unconventional reverse chiral properties of two conjugate EPs allow the nonreciprocal transmission of two selective modes in the opposite directions of the underlying waveguide variants. An explicit dependence of the nonlinearity level on a significant enhancement of the nonreciprocity in terms of an isolation ratio is explored by investigating the effects of both local Kerr-type and saturable nonlinearities (considered separately). The physical insights and implications of harnessing the features of conjugate EPs in nonlinear optical systems can enable the growth and development of a versatile platform for building nonreciprocal components and devices. Close https://link.aps.org/doi/10.1103/PhysRevA.109.033511 doi:10.1103/PhysRevA.109.033511 Close
57.	Wei Qin, Adam Miranowicz, Franco Nori Proposal of ensemble qubits with two-atom decay New Journal of Physics, 26 , pp. 033006, 2024. Abstract \| Links \| BibTeX @article{Qin2024, title = {Proposal of ensemble qubits with two-atom decay}, author = {Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://iopscience.iop.org/article/10.1088/1367-2630/ad2bad}, doi = {10.1088/1367-2630/ad2bad}, year = {2024}, date = {2024-03-08}, journal = {New Journal of Physics}, volume = {26}, pages = {033006}, abstract = {We propose and analyze a novel approach to implement ensemble qubits. The required anharmonicity is provided by a simultaneous decay of two atoms (i.e. two-atom decay), which is achieved by fully quantum degenerate parametric amplification. For an atomic ensemble, the two-atom decay generates and stabilizes a 2D quantum manifold, which is spanned by the ground and single-excited superradiant states. Moreover, this nonlinear decay process can strongly suppress transitions to higher-excited superradiant states, and convert residual transitions into an effective decay from the single-excitation superradiant state to the ground state. Our method does not require Rydberg dipole blockade and, thus, strong atom-atom interactions, compared to previous work. This indicates that it can be applied to typical atomic or spin ensembles in simple experimental setups. Remarkably, our idea is compatible with the cavity protection mechanism, and therefore spin dephasing due to inhomogeneous broadening can be strongly suppressed. The presented ensemble qubit provides a new platform for quantum information processing, and also extends the range of applications of atomic or spin ensembles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose and analyze a novel approach to implement ensemble qubits. The required anharmonicity is provided by a simultaneous decay of two atoms (i.e. two-atom decay), which is achieved by fully quantum degenerate parametric amplification. For an atomic ensemble, the two-atom decay generates and stabilizes a 2D quantum manifold, which is spanned by the ground and single-excited superradiant states. Moreover, this nonlinear decay process can strongly suppress transitions to higher-excited superradiant states, and convert residual transitions into an effective decay from the single-excitation superradiant state to the ground state. Our method does not require Rydberg dipole blockade and, thus, strong atom-atom interactions, compared to previous work. This indicates that it can be applied to typical atomic or spin ensembles in simple experimental setups. Remarkably, our idea is compatible with the cavity protection mechanism, and therefore spin dephasing due to inhomogeneous broadening can be strongly suppressed. The presented ensemble qubit provides a new platform for quantum information processing, and also extends the range of applications of atomic or spin ensembles. Close https://iopscience.iop.org/article/10.1088/1367-2630/ad2bad doi:10.1088/1367-2630/ad2bad Close
56.	Marek Kopciuch, Magdalena Smolis, Adam Miranowicz, Szymon Pustelny Optimized optical tomography of quantum states of a room-temperature alkali-metal vapor Phys. Rev. A, 109 , pp. 032402, 2024. Abstract \| Links \| BibTeX @article{Kopciuch2024, title = {Optimized optical tomography of quantum states of a room-temperature alkali-metal vapor}, author = {Marek Kopciuch and Magdalena Smolis and Adam Miranowicz and Szymon Pustelny}, url = {https://link.aps.org/doi/10.1103/PhysRevA.109.032402}, doi = {10.1103/PhysRevA.109.032402}, year = {2024}, date = {2024-03-01}, journal = {Phys. Rev. A}, volume = {109}, pages = {032402}, abstract = {We demonstrate an experimental technique for the quantum-state tomography of the collective qutrit states of a room-temperature alkali-metal vapor. It is based on the measurements of the polarization of light traversing the vapor subjected to a magnetic field. To assess the technique's robustness against errors, experimental investigations are supported with numerical simulations. This not only allows us to determine the fidelity of the reconstructed states, but also to analyze the quality of the reconstruction for specific experimental parameters, such as light tuning and the number of measurements. By utilizing the conditional number, we demonstrate that the reconstruction robustness can be optimized by a proper adjustment of experimental parameters, and further improvement is possible with the repetition of specific measurements. Our results demonstrate the potential of this high-fidelity reconstruction method of quantum states of room-temperature atomic vapors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We demonstrate an experimental technique for the quantum-state tomography of the collective qutrit states of a room-temperature alkali-metal vapor. It is based on the measurements of the polarization of light traversing the vapor subjected to a magnetic field. To assess the technique's robustness against errors, experimental investigations are supported with numerical simulations. This not only allows us to determine the fidelity of the reconstructed states, but also to analyze the quality of the reconstruction for specific experimental parameters, such as light tuning and the number of measurements. By utilizing the conditional number, we demonstrate that the reconstruction robustness can be optimized by a proper adjustment of experimental parameters, and further improvement is possible with the repetition of specific measurements. Our results demonstrate the potential of this high-fidelity reconstruction method of quantum states of room-temperature atomic vapors. Close https://link.aps.org/doi/10.1103/PhysRevA.109.032402 doi:10.1103/PhysRevA.109.032402 Close
55.	Ye-Hong Chen, Yuan Qiu, Adam Miranowicz, Neill Lambert, Wei Qin, Roberto Stassi, Yan Xia, Shi-Biao Zheng, Franco Nori Sudden change of the photon output field marks phase transitions in the quantum Rabi model Communications Physics, 7 (5), 2024. Abstract \| Links \| BibTeX @article{Chen2024, title = {Sudden change of the photon output field marks phase transitions in the quantum Rabi model}, author = {Ye-Hong Chen and Yuan Qiu and Adam Miranowicz and Neill Lambert and Wei Qin and Roberto Stassi and Yan Xia and Shi-Biao Zheng and Franco Nori}, url = {https://www.nature.com/articles/s42005-023-01457-w}, doi = {10.1038/s42005-023-01457-w}, year = {2024}, date = {2024-01-05}, journal = {Communications Physics}, volume = {7}, number = {5}, abstract = {The experimental observation of quantum phase transitions predicted by the quantum Rabi model in quantum critical systems is usually challenging due to the lack of signature experimental observables associated with them. Here, we describe a method to identify the dynamical critical phenomenon in the quantum Rabi model consisting of a three-level atom and a cavity at the quantum phase transition. Such a critical phenomenon manifests itself as a sudden change of steady-state output photons in the system driven by two classical fields, when both the atom and the cavity are initially unexcited. The process occurs as the high-frequency pump field is converted into the low-frequency Stokes field and multiple cavity photons in the normal phase, while this conversion cannot occur in the superradiant phase. The sudden change of steady-state output photons is an experimentally accessible measure to probe quantum phase transitions, as it does not require preparing the equilibrium state.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The experimental observation of quantum phase transitions predicted by the quantum Rabi model in quantum critical systems is usually challenging due to the lack of signature experimental observables associated with them. Here, we describe a method to identify the dynamical critical phenomenon in the quantum Rabi model consisting of a three-level atom and a cavity at the quantum phase transition. Such a critical phenomenon manifests itself as a sudden change of steady-state output photons in the system driven by two classical fields, when both the atom and the cavity are initially unexcited. The process occurs as the high-frequency pump field is converted into the low-frequency Stokes field and multiple cavity photons in the normal phase, while this conversion cannot occur in the superradiant phase. The sudden change of steady-state output photons is an experimentally accessible measure to probe quantum phase transitions, as it does not require preparing the equilibrium state. Close https://www.nature.com/articles/s42005-023-01457-w doi:10.1038/s42005-023-01457-w Close
54.	Josef Kadlec, Karol Bartkiewicz, Antonín Černoch, Karel Lemr, Adam Miranowicz Experimental hierarchy of the nonclassicality of single-qubit states via potentials for entanglement, steering, and Bell nonlocality Opt. Express, 32 (2), pp. 2333–2346, 2024. Abstract \| Links \| BibTeX @article{Kadlec:24, title = {Experimental hierarchy of the nonclassicality of single-qubit states via potentials for entanglement, steering, and Bell nonlocality}, author = {Josef Kadlec and Karol Bartkiewicz and Antonín Černoch and Karel Lemr and Adam Miranowicz}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-32-2-2333}, doi = {10.1364/OE.506169}, year = {2024}, date = {2024-01-01}, journal = {Opt. Express}, volume = {32}, number = {2}, pages = {2333--2346}, publisher = {Optica Publishing Group}, abstract = {Entanglement potentials are a promising way to quantify the nonclassicality of single-mode states. They are defined by the amount of entanglement (expressed by, e.g., the Wootters concurrence) obtained after mixing the examined single-mode state with a purely classical state; such as the vacuum or a coherent state. We generalize the idea of entanglement potentials to other quantum correlations: the EPR steering and Bell nonlocality, thus enabling us to study mutual hierarchies of these nonclassicality potentials. Instead of the usual vacuum and one-photon superposition states, we experimentally test this concept using specially tailored polarization-encoded single-photon states. One polarization encodes a given nonclassical single-mode state, while the other serves as the vacuum place-holder. This technique proves to be experimentally more convenient in comparison to the vacuum and a one-photon superposition as it does not require the vacuum detection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Entanglement potentials are a promising way to quantify the nonclassicality of single-mode states. They are defined by the amount of entanglement (expressed by, e.g., the Wootters concurrence) obtained after mixing the examined single-mode state with a purely classical state; such as the vacuum or a coherent state. We generalize the idea of entanglement potentials to other quantum correlations: the EPR steering and Bell nonlocality, thus enabling us to study mutual hierarchies of these nonclassicality potentials. Instead of the usual vacuum and one-photon superposition states, we experimentally test this concept using specially tailored polarization-encoded single-photon states. One polarization encodes a given nonclassical single-mode state, while the other serves as the vacuum place-holder. This technique proves to be experimentally more convenient in comparison to the vacuum and a one-photon superposition as it does not require the vacuum detection. Close https://opg.optica.org/oe/abstract.cfm?URI=oe-32-2-2333 doi:10.1364/OE.506169 Close
53.	Jan Roik, Karol Bartkiewicz, Antonín Černoch, Karel Lemr Routing in quantum communication networks using reinforcement machine learning Quantum Information Processing, 23 (3), 2024, ISSN: 1573-1332. Links \| BibTeX @article{Roik2024, title = {Routing in quantum communication networks using reinforcement machine learning}, author = {Jan Roik and Karol Bartkiewicz and Antonín Černoch and Karel Lemr}, url = {http://dx.doi.org/10.1007/s11128-024-04287-z}, doi = {10.1007/s11128-024-04287-z}, issn = {1573-1332}, year = {2024}, date = {2024-01-01}, journal = {Quantum Information Processing}, volume = {23}, number = {3}, publisher = {Springer Science and Business Media LLC}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close http://dx.doi.org/10.1007/s11128-024-04287-z doi:10.1007/s11128-024-04287-z Close
52.	Jolanta Natalia Latosińska, Magdalena Latosińska, Janez Seliger, Veselko Žagar, Tomaž Apih Butterfly Effect in Cytarabine: Combined NMR-NQR Experiment, Solid-State Computational Modeling, Quantitative Structure-Property Relationships and Molecular Docking Study Pharmaceuticals, 17 (4), 2024, ISSN: 1424-8247. Abstract \| Links \| BibTeX @article{ph17040445, title = {Butterfly Effect in Cytarabine: Combined NMR-NQR Experiment, Solid-State Computational Modeling, Quantitative Structure-Property Relationships and Molecular Docking Study}, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Janez Seliger and Veselko Žagar and Tomaž Apih}, url = {https://www.mdpi.com/1424-8247/17/4/445}, doi = {10.3390/ph17040445}, issn = {1424-8247}, year = {2024}, date = {2024-01-01}, journal = {Pharmaceuticals}, volume = {17}, number = {4}, abstract = {Cytarabine (Ara-C) is a synthetic isomer of cytidine that differs from cytidine and deoxycytidine only in the sugar. The use of arabinose instead of deoxyribose hinders the formation of phosphodiester linkages between pentoses, preventing the DNA chain from elongation and interrupting the DNA synthesis. The minor structural alteration (the inversion of hydroxyl at the 2′ positions of the sugar) leads to change of the biological activity from anti-depressant and DNA/RNA block builder to powerful anti-cancer. Our study aimed to determine the molecular nature of this phenomenon. Three 1H-14N NMR-NQR experimental techniques, followed by solid-state computational modelling (Quantum Theory of Atoms in Molecules, Reduced Density Gradient and 3D Hirshfeld surfaces), Quantitative Structure–Property Relationships, Spackman’s Hirshfeld surfaces and Molecular Docking were used. Multifaceted analysis—combining experiments, computational modeling and molecular docking—provides deep insight into three-dimensional packing at the atomic and molecular levels, but is challenging. A spectrum with nine lines indicating the existence of three chemically inequivalent nitrogen sites in the Ara-C molecule was recorded, and the lines were assigned to them. The influence of the structural alteration on the NQR parameters was modeled in the solid (GGA/RPBE). For the comprehensive description of the nature of these interactions several factors were considered, including relative reactivity and the involvement of heavy atoms in various non-covalent interactions. The binding modes in the solid state and complex with dCK were investigated using the novel approaches: radial plots, heatmaps and root-mean-square deviation of the binding mode. We identified the intramolecular OH···O hydrogen bond as the key factor responsible for forcing the glycone conformation and strengthening NH···O bonds with Gln97, Asp133 and Ara128, and stacking with Phe137. The titular butterfly effect is associated with both the inversion and the presence of this intramolecular hydrogen bond. Our study elucidates the differences in the binding modes of Ara-C and cytidine, which should guide the design of more potent anti-cancer and anti-viral analogues.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Cytarabine (Ara-C) is a synthetic isomer of cytidine that differs from cytidine and deoxycytidine only in the sugar. The use of arabinose instead of deoxyribose hinders the formation of phosphodiester linkages between pentoses, preventing the DNA chain from elongation and interrupting the DNA synthesis. The minor structural alteration (the inversion of hydroxyl at the 2′ positions of the sugar) leads to change of the biological activity from anti-depressant and DNA/RNA block builder to powerful anti-cancer. Our study aimed to determine the molecular nature of this phenomenon. Three 1H-14N NMR-NQR experimental techniques, followed by solid-state computational modelling (Quantum Theory of Atoms in Molecules, Reduced Density Gradient and 3D Hirshfeld surfaces), Quantitative Structure–Property Relationships, Spackman’s Hirshfeld surfaces and Molecular Docking were used. Multifaceted analysis—combining experiments, computational modeling and molecular docking—provides deep insight into three-dimensional packing at the atomic and molecular levels, but is challenging. A spectrum with nine lines indicating the existence of three chemically inequivalent nitrogen sites in the Ara-C molecule was recorded, and the lines were assigned to them. The influence of the structural alteration on the NQR parameters was modeled in the solid (GGA/RPBE). For the comprehensive description of the nature of these interactions several factors were considered, including relative reactivity and the involvement of heavy atoms in various non-covalent interactions. The binding modes in the solid state and complex with dCK were investigated using the novel approaches: radial plots, heatmaps and root-mean-square deviation of the binding mode. We identified the intramolecular OH···O hydrogen bond as the key factor responsible for forcing the glycone conformation and strengthening NH···O bonds with Gln97, Asp133 and Ara128, and stacking with Phe137. The titular butterfly effect is associated with both the inversion and the presence of this intramolecular hydrogen bond. Our study elucidates the differences in the binding modes of Ara-C and cytidine, which should guide the design of more potent anti-cancer and anti-viral analogues. Close https://www.mdpi.com/1424-8247/17/4/445 doi:10.3390/ph17040445 Close
51.	Magdalena Latosińska, Jolanta Natalia Latosińska Favipiravir Analogues as Inhibitors of SARS-CoV-2 RNA-Dependent RNA Polymerase, Combined Quantum Chemical Modeling, Quantitative Structure–Property Relationship, and Molecular Docking Study Molecules, 29 (2), pp. 441, 2024, ISSN: 1420-3049. Links \| BibTeX @article{Latosiska2024, title = {Favipiravir Analogues as Inhibitors of SARS-CoV-2 RNA-Dependent RNA Polymerase, Combined Quantum Chemical Modeling, Quantitative Structure–Property Relationship, and Molecular Docking Study}, author = {Magdalena Latosińska and Jolanta Natalia Latosińska}, url = {http://dx.doi.org/10.3390/molecules29020441}, doi = {10.3390/molecules29020441}, issn = {1420-3049}, year = {2024}, date = {2024-01-01}, journal = {Molecules}, volume = {29}, number = {2}, pages = {441}, publisher = {MDPI AG}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close http://dx.doi.org/10.3390/molecules29020441 doi:10.3390/molecules29020441 Close
50.	E S Hevorkian, V P Nerubatskyi, R V Vovk, T Szumiata, Jolanta Natalia Latosińska Foamy ceramic filters and new possibilities of their applications Ceramics International, 50 (4), pp. 6961–6968, 2024, ISSN: 0272-8842. Links \| BibTeX @article{Hevorkian2024b, title = {Foamy ceramic filters and new possibilities of their applications}, author = {E S Hevorkian and V P Nerubatskyi and R V Vovk and T Szumiata and Jolanta Natalia Latosińska}, url = {http://dx.doi.org/10.1016/j.ceramint.2023.12.046}, doi = {10.1016/j.ceramint.2023.12.046}, issn = {0272-8842}, year = {2024}, date = {2024-01-01}, journal = {Ceramics International}, volume = {50}, number = {4}, pages = {6961–6968}, publisher = {Elsevier BV}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close http://dx.doi.org/10.1016/j.ceramint.2023.12.046 doi:10.1016/j.ceramint.2023.12.046 Close
2023
49.	Andrzej Grudka, Jȩdrzej Stempin, Jan Wójcik, Antoni Wójcik Superluminal observers do not explain quantum superpositions Physics Letters A, 487 , pp. 129127, 2023. Abstract \| Links \| BibTeX @article{Grudka2023, title = {Superluminal observers do not explain quantum superpositions}, author = {Andrzej Grudka and Jȩdrzej Stempin and Jan Wójcik and Antoni Wójcik}, url = {https://www.sciencedirect.com/science/article/pii/S0375960123005078}, doi = {10.1016/j.physleta.2023.129127}, year = {2023}, date = {2023-11-05}, journal = {Physics Letters A}, volume = {487}, pages = {129127}, abstract = {The quantum description of reality is quite different from the classical one. Understanding this difference at a fundamental level is still an interesting topic. Recently, Dragan and Ekert (2020) postulated that considering so-called superluminal observers can be useful in this context. In particular, they claim that the full mathematical structure of the generalized Lorentz transformation may imply the emergence of multiple quantum mechanical trajectories. On the contrary, here we show that the generalized Lorentz transformation, when used in a consistent way, does not provide any correspondence between the classical concept of a definite path and the multiple paths of quantum mechanics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The quantum description of reality is quite different from the classical one. Understanding this difference at a fundamental level is still an interesting topic. Recently, Dragan and Ekert (2020) postulated that considering so-called superluminal observers can be useful in this context. In particular, they claim that the full mathematical structure of the generalized Lorentz transformation may imply the emergence of multiple quantum mechanical trajectories. On the contrary, here we show that the generalized Lorentz transformation, when used in a consistent way, does not provide any correspondence between the classical concept of a definite path and the multiple paths of quantum mechanics. Close https://www.sciencedirect.com/science/article/pii/S0375960123005078 doi:10.1016/j.physleta.2023.129127 Close
48.	Ievgen I. Arkhipov, Adam Miranowicz, Franco Nori, Şahin K. Özdemir, Fabrizio Minganti Fully solvable finite simplex lattices with open boundaries in arbitrary dimensions Phys. Rev. Res., 5 , pp. 043092, 2023. Abstract \| Links \| BibTeX @article{Arkhipov2023b, title = {Fully solvable finite simplex lattices with open boundaries in arbitrary dimensions}, author = {Ievgen I. Arkhipov and Adam Miranowicz and Franco Nori and Şahin K. Özdemir and Fabrizio Minganti}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.5.043092}, doi = {10.1103/PhysRevResearch.5.043092}, year = {2023}, date = {2023-10-26}, journal = {Phys. Rev. Res.}, volume = {5}, pages = {043092}, abstract = {Finite simplex lattice models are used in different branches of science, e.g., in condensed-matter physics, when studying frustrated magnetic systems and non-Hermitian localization phenomena; or in chemistry, when describing experiments with mixtures. An n-simplex represents the simplest possible polytope in n dimensions, e.g., a line segment, a triangle, and a tetrahedron in one, two, and three dimensions, respectively. In this work, we show that various fully solvable, in general non-Hermitian, n-simplex lattice models with open boundaries can be constructed from the high-order field-moments space of quadratic bosonic systems. Namely, we demonstrate that such n-simplex lattices can be formed by a dimensional reduction of highly degenerate iterated polytope chains in (k>n)-dimensions, which naturally emerge in the field-moments space. Our findings indicate that the field-moments space of bosonic systems provides a versatile platform for simulating real-space n-simplex lattices exhibiting non-Hermitian phenomena, and it yields valuable insights into the structure of many-body systems exhibiting similar complexity. Among a variety of practical applications, these simplex structures can offer a physical setting for implementing the discrete fractional Fourier transform, an indispensable tool for both quantum and classical signal processing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Finite simplex lattice models are used in different branches of science, e.g., in condensed-matter physics, when studying frustrated magnetic systems and non-Hermitian localization phenomena; or in chemistry, when describing experiments with mixtures. An n-simplex represents the simplest possible polytope in n dimensions, e.g., a line segment, a triangle, and a tetrahedron in one, two, and three dimensions, respectively. In this work, we show that various fully solvable, in general non-Hermitian, n-simplex lattice models with open boundaries can be constructed from the high-order field-moments space of quadratic bosonic systems. Namely, we demonstrate that such n-simplex lattices can be formed by a dimensional reduction of highly degenerate iterated polytope chains in (k>n)-dimensions, which naturally emerge in the field-moments space. Our findings indicate that the field-moments space of bosonic systems provides a versatile platform for simulating real-space n-simplex lattices exhibiting non-Hermitian phenomena, and it yields valuable insights into the structure of many-body systems exhibiting similar complexity. Among a variety of practical applications, these simplex structures can offer a physical setting for implementing the discrete fractional Fourier transform, an indispensable tool for both quantum and classical signal processing. Close https://link.aps.org/doi/10.1103/PhysRevResearch.5.043092 doi:10.1103/PhysRevResearch.5.043092 Close
47.	Jan Peřina, Jr., Adam Miranowicz, Joanna K. Kalaga, Wiesław Leoński Unavoidability of nonclassicality loss in PT-symmetric systems Phys. Rev. A, 108 , pp. 033512, 2023. Abstract \| Links \| BibTeX @article{Peřina2023, title = {Unavoidability of nonclassicality loss in PT-symmetric systems}, author = {Jan Peřina, Jr. and Adam Miranowicz and Joanna K. Kalaga and Wiesław Leoński}, url = {https://journals.aps.org/pra/abstract/10.1103/PhysRevA.108.033512}, doi = {10.1103/PhysRevA.108.033512}, year = {2023}, date = {2023-09-15}, journal = {Phys. Rev. A}, volume = {108}, pages = {033512}, abstract = {We show that the loss of nonclassicality (including quantum entanglement) cannot be compensated by the (incoherent) amplification of PT-symmetric systems. We address this problem by manipulating the quantum fluctuating forces in the Heisenberg-Langevin approach. Specifically, we analyze the dynamics of two nonlinearly coupled oscillator modes in a PT-symmetric system. An analytical solution allows us to separate the contribution of reservoir fluctuations from the evolution of quantum statistical properties of the modes. In general, as reservoir fluctuations act constantly, the complete loss of nonclassicality and entanglement is observed for long times. To elucidate the role of reservoir fluctuations in a long-time evolution of nonclassicality and entanglement, we consider and compare the predictions from two alternative models in which no fatal long-time detrimental effects on the nonclassicality and entanglement are observed. This is so as, in the first semiclassical model, no reservoir fluctuations are considered at all. This, however, violates the fluctuation-dissipation theorem. The second, more elaborated, model obeys the fluctuation-dissipation relations as it partly involves reservoir fluctuations. However, to prevent the above long-time detrimental effects, the reservoir fluctuations have to be endowed with the nonphysical properties of a sink model. In both models, additional incorporation of the omitted reservoir fluctuations results in their physically consistent behavior. This behavior, however, predicts the gradual loss of the nonclassicality and entanglement. Thus the effects of reservoir fluctuations related to damping cannot be compensated by those related to amplification. This qualitatively differs from the influence of damping and amplification to a direct coherent dynamics of PT-symmetric systems in which their mutual interference results in a periodic behavior allowing for nonclassicality and entanglement at arbitrary times.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We show that the loss of nonclassicality (including quantum entanglement) cannot be compensated by the (incoherent) amplification of PT-symmetric systems. We address this problem by manipulating the quantum fluctuating forces in the Heisenberg-Langevin approach. Specifically, we analyze the dynamics of two nonlinearly coupled oscillator modes in a PT-symmetric system. An analytical solution allows us to separate the contribution of reservoir fluctuations from the evolution of quantum statistical properties of the modes. In general, as reservoir fluctuations act constantly, the complete loss of nonclassicality and entanglement is observed for long times. To elucidate the role of reservoir fluctuations in a long-time evolution of nonclassicality and entanglement, we consider and compare the predictions from two alternative models in which no fatal long-time detrimental effects on the nonclassicality and entanglement are observed. This is so as, in the first semiclassical model, no reservoir fluctuations are considered at all. This, however, violates the fluctuation-dissipation theorem. The second, more elaborated, model obeys the fluctuation-dissipation relations as it partly involves reservoir fluctuations. However, to prevent the above long-time detrimental effects, the reservoir fluctuations have to be endowed with the nonphysical properties of a sink model. In both models, additional incorporation of the omitted reservoir fluctuations results in their physically consistent behavior. This behavior, however, predicts the gradual loss of the nonclassicality and entanglement. Thus the effects of reservoir fluctuations related to damping cannot be compensated by those related to amplification. This qualitatively differs from the influence of damping and amplification to a direct coherent dynamics of PT-symmetric systems in which their mutual interference results in a periodic behavior allowing for nonclassicality and entanglement at arbitrary times. Close https://journals.aps.org/pra/abstract/10.1103/PhysRevA.108.033512 doi:10.1103/PhysRevA.108.033512 Close
46.	Jolanta Natalia Latosińska, Magdalena Latosińska, Janez Seliger, Veselko Žagar Exploring Partial Structural Disorder in Anhydrous Paraxanthine through Combined Experiment, Solid-State Computational Modelling, and Molecular Docking Processes, 11 (9), 2023, ISSN: 2227-9717. Abstract \| Links \| BibTeX @article{pr11092740, title = {Exploring Partial Structural Disorder in Anhydrous Paraxanthine through Combined Experiment, Solid-State Computational Modelling, and Molecular Docking}, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Janez Seliger and Veselko Žagar}, url = {https://www.mdpi.com/2227-9717/11/9/2740}, doi = {10.3390/pr11092740}, issn = {2227-9717}, year = {2023}, date = {2023-09-14}, journal = {Processes}, volume = {11}, number = {9}, abstract = {Paraxanthine (PX), a major metabolite of caffeine, a protective agent against Alzheimer’s and Parkinson’s disease, and a promising drug for the treatment of post-COVID 2019 anosmia and ageusia, has been studied in the solid state and protein–ligand complex. Partial disorder in PX, caused by the methyl group at the N(7) position, has been modelled and discussed. The relationship between the unusual structural disorder and the propensity to form a specific system of non-covalent bonds was analyzed. Three 1H-14N NMR-NQR (nuclear magnetic resonance–nuclear quadrupole resonance) experimental techniques were used, namely multiple frequency sweeps, Larmor frequency scanning, and the two-frequency irradiation, followed by solid-state computational modelling (density functional theory, supplemented by quantum theory of atoms in molecules, 3D Hirshfeld surfaces, and reduced density gradient), and molecular docking approaches. New quantitative methods for estimating changes in the global pattern of interactions under the influence of rotation of the methyl group in N(7) based on the Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance have been proposed and applied. A spectrum consisting of 12 lines, indicating the presence of 4 chemically inequivalent nitrogen sites in the PX molecule, was recorded, and the lines’ assignment to particular sites was made. The influence of the methyl rotation on the eigenvalues and eigenvectors of the electric field gradient tensor, NQR parameters, and resonance line positions was modelled in the solid (GGA/RPBE, m-GGA/RSCAN) and cluster (Minnesota M062X hybrid). Three factors have been found to determine structural disorder in PX: larger crystal voids near the methyl at N(7) than at N(1) (opening the path for the disorder), hyperconjugation strongly affecting the density distribution in the five-membered ring, and the involvement of the methyl group at N(7) in many non-covalent bonds that intercept (capture) subsequent jumping protons. The Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance confirmed the changes in the distribution and strength of non-covalent interactions throughout the molecule as a result of methyl rotation. This effect is clearly visible regardless of the type of metric, and its order of magnitude is consistent with the modulation effect of the NQR spectra (experimental and calculated). Through molecular docking, it was discovered that the PX moiety in protein–ligand complexes adopt the same methyl group conformation at N(7) as in the solid state. It was found that the cooperation–competition between the C-H⋯O hydrogen bonds and C-H⋯H-C dispersion interactions is the crucial factor that impedes methyl rotation and induces structural disorder, as well as being an important factor in the formation of the protein–ligand complexes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Paraxanthine (PX), a major metabolite of caffeine, a protective agent against Alzheimer’s and Parkinson’s disease, and a promising drug for the treatment of post-COVID 2019 anosmia and ageusia, has been studied in the solid state and protein–ligand complex. Partial disorder in PX, caused by the methyl group at the N(7) position, has been modelled and discussed. The relationship between the unusual structural disorder and the propensity to form a specific system of non-covalent bonds was analyzed. Three 1H-14N NMR-NQR (nuclear magnetic resonance–nuclear quadrupole resonance) experimental techniques were used, namely multiple frequency sweeps, Larmor frequency scanning, and the two-frequency irradiation, followed by solid-state computational modelling (density functional theory, supplemented by quantum theory of atoms in molecules, 3D Hirshfeld surfaces, and reduced density gradient), and molecular docking approaches. New quantitative methods for estimating changes in the global pattern of interactions under the influence of rotation of the methyl group in N(7) based on the Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance have been proposed and applied. A spectrum consisting of 12 lines, indicating the presence of 4 chemically inequivalent nitrogen sites in the PX molecule, was recorded, and the lines’ assignment to particular sites was made. The influence of the methyl rotation on the eigenvalues and eigenvectors of the electric field gradient tensor, NQR parameters, and resonance line positions was modelled in the solid (GGA/RPBE, m-GGA/RSCAN) and cluster (Minnesota M062X hybrid). Three factors have been found to determine structural disorder in PX: larger crystal voids near the methyl at N(7) than at N(1) (opening the path for the disorder), hyperconjugation strongly affecting the density distribution in the five-membered ring, and the involvement of the methyl group at N(7) in many non-covalent bonds that intercept (capture) subsequent jumping protons. The Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance confirmed the changes in the distribution and strength of non-covalent interactions throughout the molecule as a result of methyl rotation. This effect is clearly visible regardless of the type of metric, and its order of magnitude is consistent with the modulation effect of the NQR spectra (experimental and calculated). Through molecular docking, it was discovered that the PX moiety in protein–ligand complexes adopt the same methyl group conformation at N(7) as in the solid state. It was found that the cooperation–competition between the C-H⋯O hydrogen bonds and C-H⋯H-C dispersion interactions is the crucial factor that impedes methyl rotation and induces structural disorder, as well as being an important factor in the formation of the protein–ligand complexes. Close https://www.mdpi.com/2227-9717/11/9/2740 doi:10.3390/pr11092740 Close
45.	Ri-Hua Zheng, Wen Ning, Ye-Hong Chen, Jia-Hao Lü, Li-Tuo Shen, Kai Xu, Yu-Ran Zhang, Da Xu, Hekang Li, Yan Xia, Fan Wu, Zhen-Biao Yang, Adam Miranowicz, Neill Lambert, Dongning Zheng, Heng Fan, Franco Nori, Shi-Biao Zheng Observation of a Superradiant Phase Transition with Emergent Cat States Phys. Rev. Lett., 131 , pp. 113601 , 2023. Abstract \| Links \| BibTeX @article{Zheng2023, title = {Observation of a Superradiant Phase Transition with Emergent Cat States}, author = {Ri-Hua Zheng and Wen Ning and Ye-Hong Chen and Jia-Hao Lü and Li-Tuo Shen and Kai Xu and Yu-Ran Zhang and Da Xu and Hekang Li and Yan Xia and Fan Wu and Zhen-Biao Yang and Adam Miranowicz and Neill Lambert and Dongning Zheng and Heng Fan and Franco Nori and Shi-Biao Zheng}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.113601}, doi = {10.1103/PhysRevLett.131.113601}, year = {2023}, date = {2023-09-11}, journal = {Phys. Rev. Lett.}, volume = {131}, pages = {113601 }, abstract = {Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level, and play a central role in criticality-enhanced quantum sensing. So far, SPTs have been observed in driven-dissipative systems, but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic mesoscopic superposition, and reveal light-matter entanglement.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level, and play a central role in criticality-enhanced quantum sensing. So far, SPTs have been observed in driven-dissipative systems, but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic mesoscopic superposition, and reveal light-matter entanglement. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.113601 doi:10.1103/PhysRevLett.131.113601 Close
44.	Karol Bartkiewicz, Patrycja Tulewicz, Jan Roik, Karel Lemr Synergic quantum generative machine learning Scientific Reports, 13 (1), pp. 12893, 2023, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{bartkiewicz_synergic_2023, title = {Synergic quantum generative machine learning}, author = {Karol Bartkiewicz and Patrycja Tulewicz and Jan Roik and Karel Lemr}, url = {https://www.nature.com/articles/s41598-023-40137-1}, doi = {10.1038/s41598-023-40137-1}, issn = {2045-2322}, year = {2023}, date = {2023-08-09}, urldate = {2023-10-18}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {12893}, abstract = {We introduce a new approach towards generative quantum machine learning significantly reducing the number of hyperparameters and report on a proof-of-principle experiment demonstrating our approach. Our proposal depends on collaboration between the generators and discriminator, thus, we call it quantum synergic generative learning. We present numerical evidence that the synergic approach, in some cases, compares favorably to recently proposed quantum generative adversarial learning. In addition to the results obtained with quantum simulators, we also present experimental results obtained with an actual programmable quantum computer. We investigate how a quantum computer implementing generative learning algorithm could learn the concept of a maximally-entangled state. After completing the learning process, the network is able both to recognize and to generate an entangled state. Our approach can be treated as one possible preliminary step to understanding how the concept of quantum entanglement can be learned and demonstrated by a quantum computer.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We introduce a new approach towards generative quantum machine learning significantly reducing the number of hyperparameters and report on a proof-of-principle experiment demonstrating our approach. Our proposal depends on collaboration between the generators and discriminator, thus, we call it quantum synergic generative learning. We present numerical evidence that the synergic approach, in some cases, compares favorably to recently proposed quantum generative adversarial learning. In addition to the results obtained with quantum simulators, we also present experimental results obtained with an actual programmable quantum computer. We investigate how a quantum computer implementing generative learning algorithm could learn the concept of a maximally-entangled state. After completing the learning process, the network is able both to recognize and to generate an entangled state. Our approach can be treated as one possible preliminary step to understanding how the concept of quantum entanglement can be learned and demonstrated by a quantum computer. Close https://www.nature.com/articles/s41598-023-40137-1 doi:10.1038/s41598-023-40137-1 Close
43.	Andrzej Grudka, Paweł Kurzyński, Tomasz P Polak, Adam S Sajna, Jan Wójcik, Antoni Wójcik Complementarity in quantum walks Journal of Physics A, 56 , pp. 275303, 2023. Abstract \| Links \| BibTeX @article{grudka23-2, title = {Complementarity in quantum walks}, author = {Andrzej Grudka and Paweł Kurzyński and Tomasz P Polak and Adam S Sajna and Jan Wójcik and Antoni Wójcik}, doi = {10.1088/1751-8121/acdcd0}, year = {2023}, date = {2023-06-19}, journal = {Journal of Physics A}, volume = {56}, pages = {275303}, abstract = {The eigenbases of two quantum observables, {\|ai⟩}Di=1 and {\|bj⟩}Dj=1, form mutually unbiased bases (MUB) if \|⟨ai \|bj⟩\| = 1/ √D for all i and j. In realistic situations MUB are hard to obtain and one looks for approximate MUB (AMUB), in which case the corresponding eigenbases obey \|⟨ai \|bj⟩\| ⩽ c/√D, where c is some positive constant independent of D. In majority of cases observables corresponding to MUB and AMUB do not have clear physical interpretation. Here we study discrete-time quantum walks (QWs) on d-cycles with a position and coin-dependent phase-shift. Such a model simulates a dynamics of a quantum particle moving on a ring with an artificial gauge field. In our case the amplitude of the phase-shift is governed by a single discrete parameter q. We solve the model analytically and observe that for prime d the eigenvectors of two QW evolution operators form AMUB. Namely, if d is prime the corresponding eigenvectors of the evolution operators, that act in the D-dimensional Hilbert space (D = 2d), obey \|⟨vq\|v ′q ′ ⟩\| ⩽√2/√D for q ̸= q ′ and for all \|vq⟩ and \|v ′q ′ ⟩. Finally, we show that the analogous AMUB relation still holds in the continuous version of this model, which corresponds to a one-dimensional Dirac particle.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The eigenbases of two quantum observables, {\|ai⟩}Di=1 and {\|bj⟩}Dj=1, form mutually unbiased bases (MUB) if \|⟨ai \|bj⟩\| = 1/ √D for all i and j. In realistic situations MUB are hard to obtain and one looks for approximate MUB (AMUB), in which case the corresponding eigenbases obey \|⟨ai \|bj⟩\| ⩽ c/√D, where c is some positive constant independent of D. In majority of cases observables corresponding to MUB and AMUB do not have clear physical interpretation. Here we study discrete-time quantum walks (QWs) on d-cycles with a position and coin-dependent phase-shift. Such a model simulates a dynamics of a quantum particle moving on a ring with an artificial gauge field. In our case the amplitude of the phase-shift is governed by a single discrete parameter q. We solve the model analytically and observe that for prime d the eigenvectors of two QW evolution operators form AMUB. Namely, if d is prime the corresponding eigenvectors of the evolution operators, that act in the D-dimensional Hilbert space (D = 2d), obey \|⟨vq\|v ′q ′ ⟩\| ⩽√2/√D for q ̸= q ′ and for all \|vq⟩ and \|v ′q ′ ⟩. Finally, we show that the analogous AMUB relation still holds in the continuous version of this model, which corresponds to a one-dimensional Dirac particle. Close doi:10.1088/1751-8121/acdcd0 Close
42.	Shilan Abo, Jan Soubusta, Kateřina Jiráková, Karol Bartkiewicz, Antonín Černoch, Karel Lemr, Adam Miranowicz Experimental hierarchy of two-qubit quantum correlations without state tomography Scientific Reports, 13 (1), pp. 8564, 2023, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{abo_experimental_2023, title = {Experimental hierarchy of two-qubit quantum correlations without state tomography}, author = {Shilan Abo and Jan Soubusta and Kateřina Jiráková and Karol Bartkiewicz and Antonín Černoch and Karel Lemr and Adam Miranowicz}, url = {https://www.nature.com/articles/s41598-023-35015-9}, doi = {10.1038/s41598-023-35015-9}, issn = {2045-2322}, year = {2023}, date = {2023-05-26}, urldate = {2023-10-18}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {8564}, abstract = {A Werner state, which is the singlet Bell state affected by white noise, is a prototype example of states, which can reveal a hierarchy of quantum entanglement, steering, and Bell nonlocality by controlling the amount of noise. However, experimental demonstrations of this hierarchy in a sufficient and necessary way (i.e., by applying measures or universal witnesses of these quantum correlations) have been mainly based on full quantum state tomography, corresponding to measuring at least 15 real parameters of two-qubit states. Here we report an experimental demonstration of this hierarchy by measuring only six elements of a correlation matrix depending on linear combinations of two-qubit Stokes parameters. We show that our experimental setup can also reveal the hierarchy of these quantum correlations of generalized Werner states, which are any two-qubit pure states affected by white noise.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close A Werner state, which is the singlet Bell state affected by white noise, is a prototype example of states, which can reveal a hierarchy of quantum entanglement, steering, and Bell nonlocality by controlling the amount of noise. However, experimental demonstrations of this hierarchy in a sufficient and necessary way (i.e., by applying measures or universal witnesses of these quantum correlations) have been mainly based on full quantum state tomography, corresponding to measuring at least 15 real parameters of two-qubit states. Here we report an experimental demonstration of this hierarchy by measuring only six elements of a correlation matrix depending on linear combinations of two-qubit Stokes parameters. We show that our experimental setup can also reveal the hierarchy of these quantum correlations of generalized Werner states, which are any two-qubit pure states affected by white noise. Close https://www.nature.com/articles/s41598-023-35015-9 doi:10.1038/s41598-023-35015-9 Close
41.	Ievgen I. Arkhipov, Adam Miranowicz, Fabrizio Minganti, Şahin K. Özdemir, Franco Nori Dynamically crossing diabolic points while encircling exceptional curves: A programmable symmetric-asymmetric multimode switch Nature Communications, 14 (2076), 2023. Abstract \| Links \| BibTeX @article{Arkhipov2023, title = {Dynamically crossing diabolic points while encircling exceptional curves: A programmable symmetric-asymmetric multimode switch}, author = {Ievgen I. Arkhipov and Adam Miranowicz and Fabrizio Minganti and Şahin K. Özdemir and Franco Nori}, url = {https://www.nature.com/articles/s41467-023-37275-5}, doi = {doi.org/10.1038/s41467-023-37275-5}, year = {2023}, date = {2023-04-12}, journal = {Nature Communications}, volume = {14}, number = {2076}, abstract = {Nontrivial spectral properties of non-Hermitian systems can lead to intriguing effects with no counterparts in Hermitian systems. For instance, in a two-mode photonic system, by dynamically winding around an exceptional point (EP) a controlled asymmetric-symmetric mode switching can be realized. That is, the system can either end up in one of its eigenstates, regardless of the initial eigenmode, or it can switch between the two states on demand, by simply controlling the winding direction. However, for multimode systems with higher-order EPs or multiple low-order EPs, the situation can be more involved, and the ability to control asymmetric-symmetric mode switching can be impeded, due to the breakdown of adiabaticity. Here we demonstrate that this difficulty can be overcome by winding around exceptional curves by additionally crossing diabolic points. We consider a four-mode PT-symmetric bosonic system as a platform for experimental realization of such a multimode switch. Our work provides alternative routes for light manipulations in non-Hermitian photonic setups.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Nontrivial spectral properties of non-Hermitian systems can lead to intriguing effects with no counterparts in Hermitian systems. For instance, in a two-mode photonic system, by dynamically winding around an exceptional point (EP) a controlled asymmetric-symmetric mode switching can be realized. That is, the system can either end up in one of its eigenstates, regardless of the initial eigenmode, or it can switch between the two states on demand, by simply controlling the winding direction. However, for multimode systems with higher-order EPs or multiple low-order EPs, the situation can be more involved, and the ability to control asymmetric-symmetric mode switching can be impeded, due to the breakdown of adiabaticity. Here we demonstrate that this difficulty can be overcome by winding around exceptional curves by additionally crossing diabolic points. We consider a four-mode PT-symmetric bosonic system as a platform for experimental realization of such a multimode switch. Our work provides alternative routes for light manipulations in non-Hermitian photonic setups. Close https://www.nature.com/articles/s41467-023-37275-5 doi:doi.org/10.1038/s41467-023-37275-5 Close
40.	Grzegorz Chimczak, Anna Kowalewska‑Kudłaszyk, Ewelina Lange, Karol Bartkiewicz, Jan Peřina Jr. The effect of thermal photons on exceptional points in coupled resonators. Scientific Reports, 13 , pp. 5859, 2023. Abstract \| Links \| BibTeX @article{Chimczak2023, title = {The effect of thermal photons on exceptional points in coupled resonators.}, author = {Grzegorz Chimczak and Anna Kowalewska‑Kudłaszyk and Ewelina Lange and Karol Bartkiewicz and Jan Peřina Jr.}, url = {https://www.nature.com/articles/s41598-023-32864-2}, doi = {https://doi.org/10.1038/s41598-023-32864-2}, year = {2023}, date = {2023-04-11}, journal = {Scientific Reports}, volume = {13}, pages = {5859}, abstract = {We analyse two quantum systems with hidden parity-time ( PT ) symmetry: one is an optical device, whereas another is a superconducting microwave-frequency device. To investigate their symmetry, we introduce a damping frame (DF), in which loss and gain terms for a given Hamiltonian are balanced. We show that the non-Hermitian Hamiltonians of both systems can be tuned to reach an exceptional point (EP), i.e., the point in parameter space at which a transition from broken to unbroken hidden PT symmetry takes place. We calculate a degeneracy of a Liouvillian superoperator, which is called the Liouvillian exceptional point (LEP), and show that, in the optical domain, LEP is equivalent to EP obtained from the non-Hermitian Hamiltonian (HEP). We also report breaking the equivalence between LEP and HEP by a non-zero number of thermal photons for the microwave-frequency system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We analyse two quantum systems with hidden parity-time ( PT ) symmetry: one is an optical device, whereas another is a superconducting microwave-frequency device. To investigate their symmetry, we introduce a damping frame (DF), in which loss and gain terms for a given Hamiltonian are balanced. We show that the non-Hermitian Hamiltonians of both systems can be tuned to reach an exceptional point (EP), i.e., the point in parameter space at which a transition from broken to unbroken hidden PT symmetry takes place. We calculate a degeneracy of a Liouvillian superoperator, which is called the Liouvillian exceptional point (LEP), and show that, in the optical domain, LEP is equivalent to EP obtained from the non-Hermitian Hamiltonian (HEP). We also report breaking the equivalence between LEP and HEP by a non-zero number of thermal photons for the microwave-frequency system. Close https://www.nature.com/articles/s41598-023-32864-2 doi:https://doi.org/10.1038/s41598-023-32864-2 Close
39.	Jolanta Natalia Latosińska, Magdalena Latosińska, Janez Seliger, Veselko Žagar, Tomaž Apih, Paweł Grieb Elucidating the Role of Noncovalent Interactions in Favipiravir, a Drug Active against Various Human RNA Viruses; a 1H-14N NQDR/Periodic DFT/QTAIM/RDS/3D Hirshfeld Surfaces Combined Study Molecules, 28 (8), 2023, ISSN: 1420-3049. Abstract \| Links \| BibTeX @article{molecules28083308, title = {Elucidating the Role of Noncovalent Interactions in Favipiravir, a Drug Active against Various Human RNA Viruses; a 1H-14N NQDR/Periodic DFT/QTAIM/RDS/3D Hirshfeld Surfaces Combined Study}, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Janez Seliger and Veselko Žagar and Tomaž Apih and Paweł Grieb}, url = {https://www.mdpi.com/1420-3049/28/8/3308}, doi = {10.3390/molecules28083308}, issn = {1420-3049}, year = {2023}, date = {2023-04-07}, journal = {Molecules}, volume = {28}, number = {8}, abstract = {Favipiravir (6-fluoro-3-hydroxypyrazine-2-carboxamide, FPV), an active pharmaceutical component of the drug discovered and registered in March 2014 in Japan under the name Avigan, with an indication for pandemic influenza, has been studied. The study of this compound was prompted by the idea that effective processes of recognition and binding of FPV to the nucleic acid are affected predominantly by the propensity to form intra- and intermolecular interactions. Three nuclear quadrupole resonance experimental techniques, namely 1H-14N cross-relaxation, multiple frequency sweeps, and two-frequency irradiation, followed by solid-state computational modelling (density functional theory supplemented by the quantum theory of atoms in molecules, 3D Hirshfeld Surfaces, and reduced density gradient) approaches were applied. The complete NQR spectrum consisting of nine lines indicating the presence of three chemically inequivalent nitrogen sites in the FPV molecule was detected, and the assignment of lines to particular sites was performed. The description of the nearest vicinity of all three nitrogen atoms was used to characterize the nature of the intermolecular interactions from the perspective of the local single atoms and to draw some conclusions on the nature of the interactions required for effective recognition and binding. The propensity to form the electrostatic N−H···O, N−H···N, and C−H···O intermolecular hydrogen bonds competitive with two intramolecular hydrogen bonds, strong O−H···O and very weak N−H···N, closing the 5-member ring and stiffening the structure, as well as π···π and F···F dispersive interactions, were analysed in detail. The hypothesis regarding the similarity of the interaction pattern in the solid and the RNA template was verified. It was discovered that the -NH2 group in the crystal participates in intermolecular hydrogen bonds N–H···N and N–H···O, in the precatalytic state only in N–H···O, while in the active state in N–H···N and N–H···O hydrogen bonds, which is of importance to link FVP to the RNA template. Our study elucidates the binding modes of FVP (in crystal, precatalytic, and active forms) in detail and should guide the design of more potent analogues targeting SARS-CoV-2. Strong direct binding of FVP-RTP to both the active site and cofactor discovered by us suggests a possible alternative, allosteric mechanism of FVP action, which may explain the scattering of the results of clinical trials or the synergistic effect observed in combined treatment against SARS-CoV-2.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Favipiravir (6-fluoro-3-hydroxypyrazine-2-carboxamide, FPV), an active pharmaceutical component of the drug discovered and registered in March 2014 in Japan under the name Avigan, with an indication for pandemic influenza, has been studied. The study of this compound was prompted by the idea that effective processes of recognition and binding of FPV to the nucleic acid are affected predominantly by the propensity to form intra- and intermolecular interactions. Three nuclear quadrupole resonance experimental techniques, namely 1H-14N cross-relaxation, multiple frequency sweeps, and two-frequency irradiation, followed by solid-state computational modelling (density functional theory supplemented by the quantum theory of atoms in molecules, 3D Hirshfeld Surfaces, and reduced density gradient) approaches were applied. The complete NQR spectrum consisting of nine lines indicating the presence of three chemically inequivalent nitrogen sites in the FPV molecule was detected, and the assignment of lines to particular sites was performed. The description of the nearest vicinity of all three nitrogen atoms was used to characterize the nature of the intermolecular interactions from the perspective of the local single atoms and to draw some conclusions on the nature of the interactions required for effective recognition and binding. The propensity to form the electrostatic N−H···O, N−H···N, and C−H···O intermolecular hydrogen bonds competitive with two intramolecular hydrogen bonds, strong O−H···O and very weak N−H···N, closing the 5-member ring and stiffening the structure, as well as π···π and F···F dispersive interactions, were analysed in detail. The hypothesis regarding the similarity of the interaction pattern in the solid and the RNA template was verified. It was discovered that the -NH2 group in the crystal participates in intermolecular hydrogen bonds N–H···N and N–H···O, in the precatalytic state only in N–H···O, while in the active state in N–H···N and N–H···O hydrogen bonds, which is of importance to link FVP to the RNA template. Our study elucidates the binding modes of FVP (in crystal, precatalytic, and active forms) in detail and should guide the design of more potent analogues targeting SARS-CoV-2. Strong direct binding of FVP-RTP to both the active site and cofactor discovered by us suggests a possible alternative, allosteric mechanism of FVP action, which may explain the scattering of the results of clinical trials or the synergistic effect observed in combined treatment against SARS-CoV-2. Close https://www.mdpi.com/1420-3049/28/8/3308 doi:10.3390/molecules28083308 Close
38.	Alberto Mercurio, Shilan Abo, Fabio Mauceri, Enrico Russo, Vincenzo Macrì, Adam Miranowicz, Salvatore Savasta, Omar Di Stefano Pure Dephasing of Light-Matter Systems in the Ultrastrong and Deep-Strong Coupling Regimes Phys. Rev. Lett., 130 , pp. 123601, 2023. Abstract \| Links \| BibTeX @article{Mercurio2023, title = {Pure Dephasing of Light-Matter Systems in the Ultrastrong and Deep-Strong Coupling Regimes}, author = {Alberto Mercurio and Shilan Abo and Fabio Mauceri and Enrico Russo and Vincenzo Macrì and Adam Miranowicz and Salvatore Savasta and Omar Di Stefano}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.130.123601}, doi = {10.1103/PhysRevLett.130.123601}, year = {2023}, date = {2023-03-21}, journal = {Phys. Rev. Lett.}, volume = {130}, pages = {123601}, abstract = {Pure dephasing originates from the nondissipative information exchange between quantum systems and environments, and plays a key role in both spectroscopy and quantum information technology. Often pure dephasing constitutes the main mechanism of decay of quantum correlations. Here we investigate how pure dephasing of one of the components of a hybrid quantum system affects the dephasing rate of the system transitions. We find that, in turn, the interaction, in the case of a light-matter system, can significantly affect the form of the stochastic perturbation describing the dephasing of a subsystem, depending on the adopted gauge. Neglecting this issue can lead to wrong and unphysical results when the interaction becomes comparable to the bare resonance frequencies of subsystems, which correspond to the ultrastrong and deep-strong coupling regimes. We present results for two prototypical models of cavity quantun electrodynamics: the quantum Rabi and the Hopfield model.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Pure dephasing originates from the nondissipative information exchange between quantum systems and environments, and plays a key role in both spectroscopy and quantum information technology. Often pure dephasing constitutes the main mechanism of decay of quantum correlations. Here we investigate how pure dephasing of one of the components of a hybrid quantum system affects the dephasing rate of the system transitions. We find that, in turn, the interaction, in the case of a light-matter system, can significantly affect the form of the stochastic perturbation describing the dephasing of a subsystem, depending on the adopted gauge. Neglecting this issue can lead to wrong and unphysical results when the interaction becomes comparable to the bare resonance frequencies of subsystems, which correspond to the ultrastrong and deep-strong coupling regimes. We present results for two prototypical models of cavity quantun electrodynamics: the quantum Rabi and the Hopfield model. Close https://link.aps.org/doi/10.1103/PhysRevLett.130.123601 doi:10.1103/PhysRevLett.130.123601 Close
37.	Andrzej Grudka, Marcin Karczewski, Paweł Kurzyński, Jan Wójcik, Antoni Wójcik Topological invariants in quantum walks Physical Review A, 107 , pp. 032201, 2023. Abstract \| Links \| BibTeX @article{grudka23, title = {Topological invariants in quantum walks}, author = {Andrzej Grudka and Marcin Karczewski and Paweł Kurzyński and Jan Wójcik and Antoni Wójcik}, doi = {10.1103/PhysRevA.107.032201}, year = {2023}, date = {2023-03-01}, journal = {Physical Review A}, volume = {107}, pages = {032201}, abstract = {Discrete-time quantum walks (DTQWs) provide a convenient platform for a realization of many topological phases in noninteracting systems. They often offer more possibilities than systems with a static Hamiltonian. Nevertheless, researchers are still looking for DTQW symmetries protecting topological phases and for definitions of appropriate topological invariants. Although the majority of DTQW studies on this topic focus on the so-called split-step quantum walk, two distinct topological phases can be observed in more basic models. Here we infer topological properties of the basic DTQWs directly from the mapping of the Brillouin zone to the Bloch Hamiltonian. We show that for translation-symmetric systems they can be characterized by a homotopy relative to special points. We also propose a topological invariant corresponding to this concept. This invariant indicates the number of edge states at the interface between two distinct phases.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Discrete-time quantum walks (DTQWs) provide a convenient platform for a realization of many topological phases in noninteracting systems. They often offer more possibilities than systems with a static Hamiltonian. Nevertheless, researchers are still looking for DTQW symmetries protecting topological phases and for definitions of appropriate topological invariants. Although the majority of DTQW studies on this topic focus on the so-called split-step quantum walk, two distinct topological phases can be observed in more basic models. Here we infer topological properties of the basic DTQWs directly from the mapping of the Brillouin zone to the Bloch Hamiltonian. We show that for translation-symmetric systems they can be characterized by a homotopy relative to special points. We also propose a topological invariant corresponding to this concept. This invariant indicates the number of edge states at the interface between two distinct phases. Close doi:10.1103/PhysRevA.107.032201 Close
36.	Kuan-Yi Lee, Jhen-Dong Lin, Adam Miranowicz, Franco Nori, Huan-Yu Ku, Yueh-Nan Chen Steering-enhanced quantum metrology using superpositions of noisy phase shifts Phys. Rev. Res., 5 , pp. 013103, 2023. Abstract \| Links \| BibTeX @article{23prr-lee, title = {Steering-enhanced quantum metrology using superpositions of noisy phase shifts}, author = {Kuan-Yi Lee and Jhen-Dong Lin and Adam Miranowicz and Franco Nori and Huan-Yu Ku and Yueh-Nan Chen}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.5.013103}, doi = {10.1103/PhysRevResearch.5.013103}, year = {2023}, date = {2023-02-13}, journal = {Phys. Rev. Res.}, volume = {5}, pages = {013103}, publisher = {American Physical Society}, abstract = {Quantum steering is an important correlation in quantum information theory. A recent work [Nat. Commun. 12, 2410 (2021)] showed that quantum steering is also useful for quantum metrology. Here, we extend the exploration of steering-enhanced quantum metrology from single noiseless phase shifts to superpositions of noisy phase shifts. As concrete examples, we consider a control system that manipulates a target system to pass through a superposition of either dephased or depolarized phase shifts channels. We show that using such superpositions of noisy phase shifts can suppress the effects of noise and improve metrology. Furthermore, we also implemented proof-of-principle experiments for a superposition of dephased phase shifts on the IBM quantum experience, demonstrating a clear improvement on metrology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Quantum steering is an important correlation in quantum information theory. A recent work [Nat. Commun. 12, 2410 (2021)] showed that quantum steering is also useful for quantum metrology. Here, we extend the exploration of steering-enhanced quantum metrology from single noiseless phase shifts to superpositions of noisy phase shifts. As concrete examples, we consider a control system that manipulates a target system to pass through a superposition of either dephased or depolarized phase shifts channels. We show that using such superpositions of noisy phase shifts can suppress the effects of noise and improve metrology. Furthermore, we also implemented proof-of-principle experiments for a superposition of dephased phase shifts on the IBM quantum experience, demonstrating a clear improvement on metrology. Close https://link.aps.org/doi/10.1103/PhysRevResearch.5.013103 doi:10.1103/PhysRevResearch.5.013103 Close
35.	Marceli Koralewski, Małgorzata Paprzycka Faraday effect and refractive index of some imidazolium-based room-temperature ionic liquids and magnetic ionic liquids Journal of Molecular Liquids, 375 , pp. 121375, 2023. Abstract \| Links \| BibTeX @article{Koralewski2023, title = {Faraday effect and refractive index of some imidazolium-based room-temperature ionic liquids and magnetic ionic liquids}, author = {Marceli Koralewski and Małgorzata Paprzycka}, doi = {10.1016/j.molliq.2023.121375}, year = {2023}, date = {2023-02-02}, journal = {Journal of Molecular Liquids}, volume = {375}, pages = {121375}, abstract = {Knowledge of the Faraday effect (FE) is very important in fundamental research and applications. Here, we report FE and refractive index studies for two magnetic ionic liquids (MILs), namely 1-ethyl- and 1-butyl-3-methylimidazolium tetrachloroferrate. Similar studies are also conducted for ionic liquids (ILs) that have a diamagnetic counteranion in place of [FeCl4]. The magnitudes of the Verdet constants of MILs are comparable and exhibit a negative sign. Furthermore, they are about one order larger than those of ILs with a diamagnetic counteranion of a positive sign. The Verdet constant shows monotonic variations as a function of wavelength in the range from 450 to 650 nm and is mainly related to charge transfer transitions in [FeCl4], with bands located in the UV region, though the contribution of d-d transitions in Fe+3 is negligible. A model for describing the measured Verdet constant data as a function of wavelength and temperature is given with respective values of effective Faraday A-, B-, and D-terms. The introduction of an empirical rule allows the estimation of Verdet constants of iron and imidazolium derivative based MILs, which are in some cases very high, thus indicating their potential in photonics applications. Imidazole shows a positive and nearly-two orders lower magnitude of the Verdet constant. The mixture of an MIL and acetonitrile allows the tuning of both the Verdet constant and the refractive index. The refractive indices, thermo-optic coefficients, and electronic polarizabilities of MILs are higher than those of ILs with a diamagnetic counteranion.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Knowledge of the Faraday effect (FE) is very important in fundamental research and applications. Here, we report FE and refractive index studies for two magnetic ionic liquids (MILs), namely 1-ethyl- and 1-butyl-3-methylimidazolium tetrachloroferrate. Similar studies are also conducted for ionic liquids (ILs) that have a diamagnetic counteranion in place of [FeCl4]. The magnitudes of the Verdet constants of MILs are comparable and exhibit a negative sign. Furthermore, they are about one order larger than those of ILs with a diamagnetic counteranion of a positive sign. The Verdet constant shows monotonic variations as a function of wavelength in the range from 450 to 650 nm and is mainly related to charge transfer transitions in [FeCl4], with bands located in the UV region, though the contribution of d-d transitions in Fe+3 is negligible. A model for describing the measured Verdet constant data as a function of wavelength and temperature is given with respective values of effective Faraday A-, B-, and D-terms. The introduction of an empirical rule allows the estimation of Verdet constants of iron and imidazolium derivative based MILs, which are in some cases very high, thus indicating their potential in photonics applications. Imidazole shows a positive and nearly-two orders lower magnitude of the Verdet constant. The mixture of an MIL and acetonitrile allows the tuning of both the Verdet constant and the refractive index. The refractive indices, thermo-optic coefficients, and electronic polarizabilities of MILs are higher than those of ILs with a diamagnetic counteranion. Close doi:10.1016/j.molliq.2023.121375 Close
34.	Jolanta Natalia Latosińska, Magdalena Latosińska, Andrzei Orzeszko, Jan Krzysztof Maurin Synthesis and Crystal Structure of Adamantylated 4,5,6,7-tetrahalogeno-1H-benzimidazoles Novel Multi-Target Ligands (Potential CK2, M2 and SARS-CoV-2 Inhibitors). X-ray/DFT/QTAIM/Hirshfeld Surfaces/Molecular Docking Study Molecules, 28 (1), pp. 147, 2023. Abstract \| Links \| BibTeX @article{Latosińska2023, title = {Synthesis and Crystal Structure of Adamantylated 4,5,6,7-tetrahalogeno-1H-benzimidazoles Novel Multi-Target Ligands (Potential CK2, M2 and SARS-CoV-2 Inhibitors). X-ray/DFT/QTAIM/Hirshfeld Surfaces/Molecular Docking Study }, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Andrzei Orzeszko and Jan Krzysztof Maurin }, doi = {10.3390/molecules28010147}, year = {2023}, date = {2023-01-02}, journal = {Molecules}, volume = {28}, number = {1}, pages = {147}, abstract = {A series of new congeners, 1-[2-(1-adamantyl)ethyl]-1H-benzimidazole (AB) and 1-[2-(1-adamantyl)ethyl]-4,5,6,7-tetrahalogeno-1H-benzimidazole (Hal=Cl, Br, I; tClAB, tBrAB, tIAB), have been synthesized and studied. These novel multi-target ligands combine a benzimidazole ring known to show antitumor activity and an adamantyl moiety showing anti-influenza activity. Their crystal structures were determined by X-ray, while intermolecular interactions were studied using topological Bader’s Quantum Theory of Atoms in Molecules, Hirshfeld Surfaces, CLP and PIXEL approaches. The newly synthesized compounds crystallize within two different space groups, P-1 (AB and tIAB) and P21/c (tClAB and tBrAB). A number of intramolecular hydrogen bonds, C−H⋯Hal (Hal=Cl, Br, I), were found in all halogen-containing congeners studied, but the intermolecular C−H⋯N hydrogen bond was detected only in AB and tIAB, while C−Hal⋯π only in tClAB and tBrAB. The interplay between C−H⋯N and C−H⋯Hal hydrogen bonds and a shift from the strong (C−H⋯Cl) to the very weak (C−H⋯I) attractive interactions upon Hal exchange, supplemented with Hal⋯Hal overlapping, determines the differences in the symmetry of crystalline packing and is crucial from the biological point of view. The hypothesis about the potential dual inhibitor role of the newly synthesized congeners was verified using molecular docking and the congeners were found to be pharmaceutically attractive as Human Casein Kinase 2, CK2, inhibitors, Membrane Matrix 2 Protein, M2, blockers and Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2, inhibitors. The addition of adamantyl moiety seems to broaden and modify the therapeutic indices of the 4,5,6,7-tetrahalogeno-1H-benzimidazoles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close A series of new congeners, 1-[2-(1-adamantyl)ethyl]-1H-benzimidazole (AB) and 1-[2-(1-adamantyl)ethyl]-4,5,6,7-tetrahalogeno-1H-benzimidazole (Hal=Cl, Br, I; tClAB, tBrAB, tIAB), have been synthesized and studied. These novel multi-target ligands combine a benzimidazole ring known to show antitumor activity and an adamantyl moiety showing anti-influenza activity. Their crystal structures were determined by X-ray, while intermolecular interactions were studied using topological Bader’s Quantum Theory of Atoms in Molecules, Hirshfeld Surfaces, CLP and PIXEL approaches. The newly synthesized compounds crystallize within two different space groups, P-1 (AB and tIAB) and P21/c (tClAB and tBrAB). A number of intramolecular hydrogen bonds, C−H⋯Hal (Hal=Cl, Br, I), were found in all halogen-containing congeners studied, but the intermolecular C−H⋯N hydrogen bond was detected only in AB and tIAB, while C−Hal⋯π only in tClAB and tBrAB. The interplay between C−H⋯N and C−H⋯Hal hydrogen bonds and a shift from the strong (C−H⋯Cl) to the very weak (C−H⋯I) attractive interactions upon Hal exchange, supplemented with Hal⋯Hal overlapping, determines the differences in the symmetry of crystalline packing and is crucial from the biological point of view. The hypothesis about the potential dual inhibitor role of the newly synthesized congeners was verified using molecular docking and the congeners were found to be pharmaceutically attractive as Human Casein Kinase 2, CK2, inhibitors, Membrane Matrix 2 Protein, M2, blockers and Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2, inhibitors. The addition of adamantyl moiety seems to broaden and modify the therapeutic indices of the 4,5,6,7-tetrahalogeno-1H-benzimidazoles. Close doi:10.3390/molecules28010147 Close
2022
33.	Ye-Hong Chen, Adam Miranowicz, Xi Chen, Yan Xia, Franco Nori Enhanced-Fidelity Ultrafast Geometric Quantum Computation Using Strong Classical Drives Phys. Rev. Appl., 18 , pp. 064059, 2022. Abstract \| Links \| BibTeX @article{Chen22geom, title = {Enhanced-Fidelity Ultrafast Geometric Quantum Computation Using Strong Classical Drives}, author = {Ye-Hong Chen and Adam Miranowicz and Xi Chen and Yan Xia and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevApplied.18.064059}, doi = {10.1103/PhysRevApplied.18.064059}, year = {2022}, date = {2022-12-20}, journal = {Phys. Rev. Appl.}, volume = {18}, pages = {064059}, publisher = {American Physical Society}, abstract = {We propose a general approach to implement ultrafast nonadiabatic geometric single- and two-qubit gates by employing counter-rotating effects. This protocol is compatible with most optimal control methods used in previous rotating-wave approximation (RWA) protocols; thus, it is as robust as (or even more robust than) the RWA protocols. Using counter-rotating effects allows us to apply strong drives. Therefore, we can improve the gate speed by 5–10 times compared to the RWA counterpart for implementing high-fidelity (≥99.99%) gates. Such an ultrafast evolution (nanoseconds, even picoseconds) significantly reduces the influence of decoherence (e.g., the qubit dissipation and dephasing). Moreover, because the counter-rotating effects no longer induce a gate infidelity (in both the weak and strong driving regimes), we can achieve a higher fidelity compared to the RWA protocols. Therefore, in the presence of decoherence, one can implement ultrafast geometric quantum gates with ≥99% fidelities.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose a general approach to implement ultrafast nonadiabatic geometric single- and two-qubit gates by employing counter-rotating effects. This protocol is compatible with most optimal control methods used in previous rotating-wave approximation (RWA) protocols; thus, it is as robust as (or even more robust than) the RWA protocols. Using counter-rotating effects allows us to apply strong drives. Therefore, we can improve the gate speed by 5–10 times compared to the RWA counterpart for implementing high-fidelity (≥99.99%) gates. Such an ultrafast evolution (nanoseconds, even picoseconds) significantly reduces the influence of decoherence (e.g., the qubit dissipation and dephasing). Moreover, because the counter-rotating effects no longer induce a gate infidelity (in both the weak and strong driving regimes), we can achieve a higher fidelity compared to the RWA protocols. Therefore, in the presence of decoherence, one can implement ultrafast geometric quantum gates with ≥99% fidelities. Close https://link.aps.org/doi/10.1103/PhysRevApplied.18.064059 doi:10.1103/PhysRevApplied.18.064059 Close
32.	Jan Perina Jr, Adam Miranowicz, Grzegorz Chimczak, Anna Kowalewska-Kudłaszyk Quantum Liouvillian exceptional and diabolical points for bosonic fields with quadratic Ħamiltonians: Ŧhe Ħeisenberg-Langevin equation approach Quantum, 6 , pp. 883, 2022, ISSN: 2521-327X. Abstract \| Links \| BibTeX @article{Perina2022quantum, title = {Quantum Liouvillian exceptional and diabolical points for bosonic fields with quadratic Ħamiltonians: Ŧhe Ħeisenberg-Langevin equation approach}, author = {Jan Perina Jr and Adam Miranowicz and Grzegorz Chimczak and Anna Kowalewska-Kudłaszyk}, url = {https://doi.org/10.22331/q-2022-12-22-883}, doi = {10.22331/q-2022-12-22-883}, issn = {2521-327X}, year = {2022}, date = {2022-12-10}, journal = {Quantum}, volume = {6}, pages = {883}, publisher = {Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften}, abstract = {Equivalent approaches to determine eigenfrequencies of the Liouvillians of open quantum systems are discussed using the solution of the Heisenberg-Langevin equations and the corresponding equations for operator moments. A simple damped two-level atom is analyzed to demonstrate the equivalence of both approaches. The suggested method is used to reveal the structure as well as eigenfrequencies of the dynamics matrices of the corresponding equations of motion and their degeneracies for interacting bosonic modes described by general quadratic Hamiltonians. Quantum Liouvillian exceptional and diabolical points and their degeneracies are explicitly discussed for the case of two modes. Quantum hybrid diabolical exceptional points (inherited, genuine, and induced) and hidden exceptional points, which are not recognized directly in amplitude spectra, are observed. The presented approach via the Heisenberg-Langevin equations paves the general way to a detailed analysis of quantum exceptional and diabolical points in infinitely dimensional open quantum systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Equivalent approaches to determine eigenfrequencies of the Liouvillians of open quantum systems are discussed using the solution of the Heisenberg-Langevin equations and the corresponding equations for operator moments. A simple damped two-level atom is analyzed to demonstrate the equivalence of both approaches. The suggested method is used to reveal the structure as well as eigenfrequencies of the dynamics matrices of the corresponding equations of motion and their degeneracies for interacting bosonic modes described by general quadratic Hamiltonians. Quantum Liouvillian exceptional and diabolical points and their degeneracies are explicitly discussed for the case of two modes. Quantum hybrid diabolical exceptional points (inherited, genuine, and induced) and hidden exceptional points, which are not recognized directly in amplitude spectra, are observed. The presented approach via the Heisenberg-Langevin equations paves the general way to a detailed analysis of quantum exceptional and diabolical points in infinitely dimensional open quantum systems. Close https://doi.org/10.22331/q-2022-12-22-883 doi:10.22331/q-2022-12-22-883 Close
31.	Shilan Abo, Grzegorz Chimczak, Anna Kowalewska-Kudłaszyk, Jan Peřina Jr, Ravindra W. Chhajlany, Adam Miranowicz Hybrid photon–phonon blockade Scientific Reports, 12 , pp. 17655, 2022, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{shilan2022, title = {Hybrid photon–phonon blockade}, author = {Shilan Abo and Grzegorz Chimczak and Anna Kowalewska-Kudłaszyk and Jan Peřina Jr and Ravindra W. Chhajlany and Adam Miranowicz }, url = {https://www.nature.com/articles/s41598-022-21267-4}, doi = {https://doi.org/10.1038/s41598-022-21267-4}, issn = {2045-2322}, year = {2022}, date = {2022-10-21}, journal = {Scientific Reports}, volume = {12}, pages = {17655}, abstract = {We describe a novel type of blockade in a hybrid mode generated by linear coupling of photonic and phononic modes. We refer to this effect as hybrid photon–phonon blockade and show how it can be generated and detected in a driven nonlinear optomechanical superconducting system. Thus, we study boson-number correlations in the photon, phonon, and hybrid modes in linearly coupled microwave and mechanical resonators with a superconducting qubit inserted in one of them. We find such system parameters for which we observe eight types of different combinations of either blockade or tunnelling effects (defined via the sub- and super-Poissonian statistics, respectively) for photons, phonons, and hybrid bosons. In particular, we find that the hybrid photon–phonon blockade can be generated by mixing the photonic and phononic modes which do not exhibit blockade.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We describe a novel type of blockade in a hybrid mode generated by linear coupling of photonic and phononic modes. We refer to this effect as hybrid photon–phonon blockade and show how it can be generated and detected in a driven nonlinear optomechanical superconducting system. Thus, we study boson-number correlations in the photon, phonon, and hybrid modes in linearly coupled microwave and mechanical resonators with a superconducting qubit inserted in one of them. We find such system parameters for which we observe eight types of different combinations of either blockade or tunnelling effects (defined via the sub- and super-Poissonian statistics, respectively) for photons, phonons, and hybrid bosons. In particular, we find that the hybrid photon–phonon blockade can be generated by mixing the photonic and phononic modes which do not exhibit blockade. Close https://www.nature.com/articles/s41598-022-21267-4 doi:https://doi.org/10.1038/s41598-022-21267-4 Close
30.	E.S. Gevorkyan, V.P. Nerubatskyi, R.V. Vovk, V.O. Chyshkala, S.V. Lytovchenko, O.M. Morozova, Jolanta Natalia Latosińska Features of synthesis of Y2Ti2O7 ceramics for the purpose of obtaining dispersion-strengthened steels Acta Physica Polonica A, 142 (4), pp. 529, 2022. Abstract \| Links \| BibTeX @article{latosinska2022, title = {Features of synthesis of Y2Ti2O7 ceramics for the purpose of obtaining dispersion-strengthened steels}, author = {E.S. Gevorkyan and V.P. Nerubatskyi and R.V. Vovk and V.O. Chyshkala and S.V. Lytovchenko and O.M. Morozova and Jolanta Natalia Latosińska}, url = {http://przyrbwn.icm.edu.pl/APP/SPIS/a142-4.html}, doi = {10.12693/APhysPolA.142.529}, year = {2022}, date = {2022-10-17}, journal = {Acta Physica Polonica A}, volume = {142}, number = {4}, pages = {529}, abstract = {The method of electron beam heating of a mixture of yttrium and zirconium oxides for the synthesis of complex oxides has been implemented. It is established that the applied technology of melting the mixture of oxides leads to the formation of fluorite phases. It is determined that homogenization of the initial mixture of oxides should be carried out in a high-energy mill, which will reduce the temperature and duration of the synthesis of complex oxide compounds, including the desired structure of pyrochlorine. It is proposed to improve the technique of intensive thermal influence on the process of pyrochlorine synthesis by using an equiatomic alloy Y-Ti (65 wt. Y-35 wt Ti), which has been smelted using the arc melting method in an argon atmosphere. It was found that hydrogen saturation reduces the efficiency of pyrochlorine synthesis and increases the grain size, which may be associated with grain growth at the stage of hydrogen saturation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The method of electron beam heating of a mixture of yttrium and zirconium oxides for the synthesis of complex oxides has been implemented. It is established that the applied technology of melting the mixture of oxides leads to the formation of fluorite phases. It is determined that homogenization of the initial mixture of oxides should be carried out in a high-energy mill, which will reduce the temperature and duration of the synthesis of complex oxide compounds, including the desired structure of pyrochlorine. It is proposed to improve the technique of intensive thermal influence on the process of pyrochlorine synthesis by using an equiatomic alloy Y-Ti (65 wt. Y-35 wt Ti), which has been smelted using the arc melting method in an argon atmosphere. It was found that hydrogen saturation reduces the efficiency of pyrochlorine synthesis and increases the grain size, which may be associated with grain growth at the stage of hydrogen saturation. Close http://przyrbwn.icm.edu.pl/APP/SPIS/a142-4.html doi:10.12693/APhysPolA.142.529 Close
29.	Andrzej Grudka, Antoni Wójcik Comment on 'Quantum principle of relativity' New J. Phys., 24 (9), pp. 098001, 2022. Abstract \| Links \| BibTeX @article{Grudka2022, title = {Comment on 'Quantum principle of relativity'}, author = { Andrzej Grudka and Antoni Wójcik }, url = {https://iopscience.iop.org/article/10.1088/1367-2630/ac924e/meta}, doi = {10.1088/1367-2630/ac924e}, year = {2022}, date = {2022-10-03}, journal = {New J. Phys.}, volume = {24}, number = {9}, pages = {098001}, abstract = {Recently Dragan and Ekert (2020 New. J. Phys. 22 033038) presented arguments that probabilistic dynamics inherent in the realm of quantum physics is related to the propagation of superluminal particles. Moreover they argue that existence of such particles is a natural consequence of the principle of relativity. We show that the proposed extension of the Lorentz transformation can be interpreted in a natural way without invoking superluminal phenomena.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Recently Dragan and Ekert (2020 New. J. Phys. 22 033038) presented arguments that probabilistic dynamics inherent in the realm of quantum physics is related to the propagation of superluminal particles. Moreover they argue that existence of such particles is a natural consequence of the principle of relativity. We show that the proposed extension of the Lorentz transformation can be interpreted in a natural way without invoking superluminal phenomena. Close https://iopscience.iop.org/article/10.1088/1367-2630/ac924e/meta doi:10.1088/1367-2630/ac924e Close
28.	Jan Roik, Karol Bartkiewicz, Antonín Černoch, Karel Lemr Entanglement quantification from collective measurements processed by machine learning Physics Letters A, 446 , pp. 128270, 2022, ISSN: 0375-9601. Abstract \| Links \| BibTeX @article{ROIK2022128270b, title = {Entanglement quantification from collective measurements processed by machine learning}, author = {Jan Roik and Karol Bartkiewicz and Antonín Černoch and Karel Lemr}, url = {https://www.sciencedirect.com/science/article/pii/S0375960122003528}, doi = {https://doi.org/10.1016/j.physleta.2022.128270}, issn = {0375-9601}, year = {2022}, date = {2022-09-15}, journal = {Physics Letters A}, volume = {446}, pages = {128270}, abstract = {This paper investigates how to reduce the number of measurement configurations needed for sufficiently precise entanglement quantification. Instead of analytical formulae, we employ artificial neural networks to predict the amount of entanglement in a quantum state based on results of collective measurements (simultaneous measurements on multiple instances of the investigated state). We consider collective measurement limited to two copies of the investigated state. This approach allows us to explore the precision of entanglement quantification as a function of measurement configurations in a relevant scenario for practical quantum communications. For the purpose of our research, we consider general two-qubit states and their negativity as entanglement quantifier. We outline the benefits of this approach in future quantum communication networks.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close This paper investigates how to reduce the number of measurement configurations needed for sufficiently precise entanglement quantification. Instead of analytical formulae, we employ artificial neural networks to predict the amount of entanglement in a quantum state based on results of collective measurements (simultaneous measurements on multiple instances of the investigated state). We consider collective measurement limited to two copies of the investigated state. This approach allows us to explore the precision of entanglement quantification as a function of measurement configurations in a relevant scenario for practical quantum communications. For the purpose of our research, we consider general two-qubit states and their negativity as entanglement quantifier. We outline the benefits of this approach in future quantum communication networks. Close https://www.sciencedirect.com/science/article/pii/S0375960122003528 doi:https://doi.org/10.1016/j.physleta.2022.128270 Close
27.	Wei Qin, Adam Miranowicz, Franco Nori Beating the 3 dB Limit for Intracavity Squeezing and Its Application to Nondemolition Qubit Readout Phys. Rev. Lett., 129 , pp. 123602, 2022. Abstract \| Links \| BibTeX @article{Qin2022, title = {Beating the 3 dB Limit for Intracavity Squeezing and Its Application to Nondemolition Qubit Readout}, author = {Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.123602}, doi = {10.1103/PhysRevLett.129.123602}, year = {2022}, date = {2022-09-14}, journal = {Phys. Rev. Lett.}, volume = {129}, pages = {123602}, abstract = {While the squeezing of a propagating field can, in principle, be made arbitrarily strong, the cavity-field squeezing is subject to the well-known 3 dB limit, and thus has limited applications. Here, we propose the use of a fully quantum degenerate parametric amplifier (DPA) to beat this squeezing limit. Specifically, we show that by simply applying a two-tone driving to the signal mode, the pump mode can, counterintuitively, be driven by the photon loss of the signal mode into a squeezed steady state with, in principle, an arbitrarily high degree of squeezing. Furthermore, we demonstrate that this intracavity squeezing can increase the signal-to-noise ratio of longitudinal qubit readout exponentially with the degree of squeezing. Correspondingly, an improvement of the measurement error by many orders of magnitude can be achieved even for modest parameters. In stark contrast, using intracavity squeezing of the semiclassical DPA cannot practically increase the signal-to-noise ratio and thus improve the measurement error. Our results extend the range of applications of DPAs and open up new opportunities for modern quantum technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close While the squeezing of a propagating field can, in principle, be made arbitrarily strong, the cavity-field squeezing is subject to the well-known 3 dB limit, and thus has limited applications. Here, we propose the use of a fully quantum degenerate parametric amplifier (DPA) to beat this squeezing limit. Specifically, we show that by simply applying a two-tone driving to the signal mode, the pump mode can, counterintuitively, be driven by the photon loss of the signal mode into a squeezed steady state with, in principle, an arbitrarily high degree of squeezing. Furthermore, we demonstrate that this intracavity squeezing can increase the signal-to-noise ratio of longitudinal qubit readout exponentially with the degree of squeezing. Correspondingly, an improvement of the measurement error by many orders of magnitude can be achieved even for modest parameters. In stark contrast, using intracavity squeezing of the semiclassical DPA cannot practically increase the signal-to-noise ratio and thus improve the measurement error. Our results extend the range of applications of DPAs and open up new opportunities for modern quantum technologies. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.123602 doi:10.1103/PhysRevLett.129.123602 Close
26.	Rui Xu, Deng-Gao Lai, Bang-Pin Hou, Adam Miranowicz, Franco Nori Millionfold improvement in multivibration-feedback optomechanical refrigeration via auxiliary mechanical coupling Phys. Rev. A, 106 , pp. 033509, 2022. Abstract \| Links \| BibTeX @article{Xu2022, title = {Millionfold improvement in multivibration-feedback optomechanical refrigeration via auxiliary mechanical coupling}, author = {Rui Xu and Deng-Gao Lai and Bang-Pin Hou and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/pra/abstract/10.1103/PhysRevA.106.033509}, doi = {10.1103/PhysRevA.106.033509}, year = {2022}, date = {2022-09-13}, journal = {Phys. Rev. A}, volume = {106}, pages = {033509}, abstract = {The simultaneous ground-state refrigeration of multiple vibrational modes is a prerequisite for observing significant quantum effects of multiple-vibration systems. Here we propose how to realize a large amplification in the net-refrigeration rates based on cavity optomechanics and to largely improve the cooling performance of multivibration modes beyond the resolved-sideband regime. By employing an auxiliary mechanical coupling (AMC) between two mechanical vibrations, the dark mode, which is induced by the coupling of these vibrational modes to a common optical mode and cuts off cooling channels, can be fully removed. We use fully analytical treatments for the effective mechanical susceptibilities and net-cooling rates and find that when the AMC is turned on, the amplification of the net-refrigeration rates by more than six orders of magnitude can be observed. In particular, we reveal that the simultaneous ground-state cooling beyond the resolved-sideband regime arises from the introduced AMC, without which it vanishes. Our work paves the way for quantum control of multiple vibrational modes in the bad-cavity regime.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The simultaneous ground-state refrigeration of multiple vibrational modes is a prerequisite for observing significant quantum effects of multiple-vibration systems. Here we propose how to realize a large amplification in the net-refrigeration rates based on cavity optomechanics and to largely improve the cooling performance of multivibration modes beyond the resolved-sideband regime. By employing an auxiliary mechanical coupling (AMC) between two mechanical vibrations, the dark mode, which is induced by the coupling of these vibrational modes to a common optical mode and cuts off cooling channels, can be fully removed. We use fully analytical treatments for the effective mechanical susceptibilities and net-cooling rates and find that when the AMC is turned on, the amplification of the net-refrigeration rates by more than six orders of magnitude can be observed. In particular, we reveal that the simultaneous ground-state cooling beyond the resolved-sideband regime arises from the introduced AMC, without which it vanishes. Our work paves the way for quantum control of multiple vibrational modes in the bad-cavity regime. Close https://journals.aps.org/pra/abstract/10.1103/PhysRevA.106.033509 doi:10.1103/PhysRevA.106.033509 Close
25.	Ye-Hong Chen, Roberto Stassi, Wei Qin, Adam Miranowicz, Franco Nori Fault-Tolerant Multiqubit Geometric Entangling Gates Using Photonic Cat-State Qubits Phys. Rev. Applied, 18 , pp. 024076, 2022. Abstract \| Links \| BibTeX @article{Chen2022, title = {Fault-Tolerant Multiqubit Geometric Entangling Gates Using Photonic Cat-State Qubits}, author = {Ye-Hong Chen and Roberto Stassi and Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.18.024076}, doi = {10.1103/PhysRevApplied.18.024076}, year = {2022}, date = {2022-08-29}, journal = {Phys. Rev. Applied}, volume = {18}, pages = {024076}, abstract = {We propose a theoretical protocol to implement multiqubit geometric gates (i.e., the Mølmer-Sørensen gate) using photonic cat-state qubits. These cat-state qubits stored in high-Q resonators are promising for hardware-efficient universal quantum computing. Specifically, in the limit of strong two-photon drivings, phase-flip errors of the cat-state qubits are effectively suppressed, leaving only a bit-flip error to be corrected. Because this dominant error commutes with the evolution operator, our protocol preserves the error bias, and, thus, can lower the code-capacity threshold for error correction. A geometric evolution guarantees the robustness of the protocol against stochastic noise along the evolution path. Moreover, by changing detunings of the cavity-cavity couplings at a proper time, the protocol can be robust against parameter imperfections (e.g., the total evolution time) without introducing extra noises into the system. As a result, the gate can produce multimode entangled cat states in a short time with high fidelities.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose a theoretical protocol to implement multiqubit geometric gates (i.e., the Mølmer-Sørensen gate) using photonic cat-state qubits. These cat-state qubits stored in high-Q resonators are promising for hardware-efficient universal quantum computing. Specifically, in the limit of strong two-photon drivings, phase-flip errors of the cat-state qubits are effectively suppressed, leaving only a bit-flip error to be corrected. Because this dominant error commutes with the evolution operator, our protocol preserves the error bias, and, thus, can lower the code-capacity threshold for error correction. A geometric evolution guarantees the robustness of the protocol against stochastic noise along the evolution path. Moreover, by changing detunings of the cavity-cavity couplings at a proper time, the protocol can be robust against parameter imperfections (e.g., the total evolution time) without introducing extra noises into the system. As a result, the gate can produce multimode entangled cat states in a short time with high fidelities. Close https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.18.024076 doi:10.1103/PhysRevApplied.18.024076 Close
24.	Deng-Gao Lai, Ye-Hong Chen, Wei Qin, Adam Miranowicz, Franco Nori Tripartite optomechanical entanglement via optical-dark-mode control Phys. Rev. Research, 4 , pp. 033112, 2022. Abstract \| Links \| BibTeX @article{Lai2022, title = {Tripartite optomechanical entanglement via optical-dark-mode control}, author = {Deng-Gao Lai and Ye-Hong Chen and Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.4.033112}, doi = {10.1103/PhysRevResearch.4.033112}, year = {2022}, date = {2022-08-10}, journal = {Phys. Rev. Research}, volume = {4}, pages = {033112}, abstract = {We propose how to generate a tripartite light-vibration entanglement by controlling an optical dark mode (ODM), which is induced by the coupling of two optical modes to a common vibrational mode. This ODM is decoupled from the vibration, and it can be controlled on demand by employing a synthetic gauge field, which can enable efficient switching between the ODM-unbreaking and ODM-breaking regimes. We find that the tripartite optomechanical entanglement is largely suppressed in the ODM-unbreaking regime, but it is significantly enhanced in the ODM-breaking regime. In particular, the noise robustness of quantum entanglement in the ODM-breaking regime can be more than twice than that in the ODM-unbreaking regime. This study offers a method for protecting and enhancing fragile quantum resources and for constructing noise-tolerant and dark-mode-immune quantum processors and entangled networks.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose how to generate a tripartite light-vibration entanglement by controlling an optical dark mode (ODM), which is induced by the coupling of two optical modes to a common vibrational mode. This ODM is decoupled from the vibration, and it can be controlled on demand by employing a synthetic gauge field, which can enable efficient switching between the ODM-unbreaking and ODM-breaking regimes. We find that the tripartite optomechanical entanglement is largely suppressed in the ODM-unbreaking regime, but it is significantly enhanced in the ODM-breaking regime. In particular, the noise robustness of quantum entanglement in the ODM-breaking regime can be more than twice than that in the ODM-unbreaking regime. This study offers a method for protecting and enhancing fragile quantum resources and for constructing noise-tolerant and dark-mode-immune quantum processors and entangled networks. Close https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.4.033112 doi:10.1103/PhysRevResearch.4.033112 Close
23.	Deng-Gao Lai, Wei Qin, Adam Miranowicz, Franco Nori Efficient optomechanical refrigeration of two vibrations via an auxiliary feedback loop: Giant enhancement in mechanical susceptibilities and net cooling rates Phys. Rev. Research, 4 , pp. 033102, 2022. Abstract \| Links \| BibTeX @article{Lai2022b, title = {Efficient optomechanical refrigeration of two vibrations via an auxiliary feedback loop: Giant enhancement in mechanical susceptibilities and net cooling rates}, author = {Deng-Gao Lai and Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.4.033102}, doi = {10.1103/PhysRevResearch.4.033102}, year = {2022}, date = {2022-08-05}, journal = {Phys. Rev. Research}, volume = {4}, pages = {033102}, abstract = {We propose a method to realize the simultaneous ground-state refrigeration of two vibrational modes beyond the resolved-sideband regime via an auxiliary feedback loop (AFL). This is realized by introducing the AFL to break the dark mode, which is formed by two vibrational modes coupled to a common cavity-field mode. We obtain analytical results of the effective mechanical susceptibilities and net-refrigeration rates, and find that in the presence of the AFL a giant enhancement can be achieved for these susceptibilities and refrigeration rates. Remarkably, the net-cooling rates under the AFL mechanism can be up to four orders of magnitude larger than those in cases without the AFL. Moreover, we show that the simultaneous ground-state refrigeration arises from the AFL mechanism, without which it vanishes. This is because in the absence of the AFL, the dark mode prevents energy extraction through the cooling channels. However, by introducing the AFL, dark-mode breaking rebuilds the refrigeration channels, and, as a result, leads to the simultaneous cooling of these vibrations. Our approach has remarkable flexibility and scalability and can be extended to the simultaneous refrigeration of a large number of vibrations beyond the resolved-sideband regime.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose a method to realize the simultaneous ground-state refrigeration of two vibrational modes beyond the resolved-sideband regime via an auxiliary feedback loop (AFL). This is realized by introducing the AFL to break the dark mode, which is formed by two vibrational modes coupled to a common cavity-field mode. We obtain analytical results of the effective mechanical susceptibilities and net-refrigeration rates, and find that in the presence of the AFL a giant enhancement can be achieved for these susceptibilities and refrigeration rates. Remarkably, the net-cooling rates under the AFL mechanism can be up to four orders of magnitude larger than those in cases without the AFL. Moreover, we show that the simultaneous ground-state refrigeration arises from the AFL mechanism, without which it vanishes. This is because in the absence of the AFL, the dark mode prevents energy extraction through the cooling channels. However, by introducing the AFL, dark-mode breaking rebuilds the refrigeration channels, and, as a result, leads to the simultaneous cooling of these vibrations. Our approach has remarkable flexibility and scalability and can be extended to the simultaneous refrigeration of a large number of vibrations beyond the resolved-sideband regime. Close https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.4.033102 doi:10.1103/PhysRevResearch.4.033102 Close
22.	Deng-Gao Lai, Jie-Qiao Liao, Adam Miranowicz, Franco Nori Noise-Tolerant Optomechanical Entanglement via Synthetic Magnetism Phys. Rev. Lett., 129 , pp. 063602, 2022. Abstract \| Links \| BibTeX @article{Lai2022c, title = {Noise-Tolerant Optomechanical Entanglement via Synthetic Magnetism}, author = {Deng-Gao Lai and Jie-Qiao Liao and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.063602}, doi = {10.1103/PhysRevLett.129.063602}, year = {2022}, date = {2022-08-03}, journal = {Phys. Rev. Lett.}, volume = {129}, pages = {063602}, abstract = {Entanglement of light and multiple vibrations is a key resource for multichannel quantum information processing and memory. However, entanglement generation is generally suppressed, or even fully destroyed, by the dark-mode (DM) effect induced by the coupling of multiple degenerate or near-degenerate vibrational modes to a common optical mode. Here we propose how to generate optomechanical entanglement via DM breaking induced by synthetic magnetism. We find that at nonzero temperature, light and vibrations are separable in the DM-unbreaking regime but entangled in the DM-breaking regime. Remarkably, the threshold thermal phonon number for preserving entanglement in our simulations has been observed to be up to 3 orders of magnitude stronger than that in the DM-unbreaking regime. The application of the DM-breaking mechanism to optomechanical networks can make noise-tolerant entanglement networks feasible. These results are quite general and can initiate advances in quantum resources with immunity against both dark modes and thermal noise.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Entanglement of light and multiple vibrations is a key resource for multichannel quantum information processing and memory. However, entanglement generation is generally suppressed, or even fully destroyed, by the dark-mode (DM) effect induced by the coupling of multiple degenerate or near-degenerate vibrational modes to a common optical mode. Here we propose how to generate optomechanical entanglement via DM breaking induced by synthetic magnetism. We find that at nonzero temperature, light and vibrations are separable in the DM-unbreaking regime but entangled in the DM-breaking regime. Remarkably, the threshold thermal phonon number for preserving entanglement in our simulations has been observed to be up to 3 orders of magnitude stronger than that in the DM-unbreaking regime. The application of the DM-breaking mechanism to optomechanical networks can make noise-tolerant entanglement networks feasible. These results are quite general and can initiate advances in quantum resources with immunity against both dark modes and thermal noise. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.063602 doi:10.1103/PhysRevLett.129.063602 Close
21.	Huan-Yu Ku, Josef Kadlec, Antonín Černoch, Marco Túlio Quintino, Wenbin Zhou, Karel Lemr, Neill Lambert, Adam Miranowicz, Shin-Liang Chen, Franco Nori, Yueh-Nan Chen Quantifying Quantumness of Channels Without Entanglement PRX Quantum, 3 , pp. 020338, 2022. Abstract \| Links \| BibTeX @article{Ku2022, title = {Quantifying Quantumness of Channels Without Entanglement}, author = {Huan-Yu Ku and Josef Kadlec and Antonín Černoch and Marco Túlio Quintino and Wenbin Zhou and Karel Lemr and Neill Lambert and Adam Miranowicz and Shin-Liang Chen and Franco Nori and Yueh-Nan Chen}, url = {https://journals.aps.org/prxquantum/abstract/10.1103/PRXQuantum.3.020338}, doi = {10.1103/PRXQuantum.3.020338}, year = {2022}, date = {2022-05-19}, journal = {PRX Quantum}, volume = {3}, pages = {020338}, abstract = {Quantum channels breaking entanglement, incompatibility, or nonlocality are defined as such because they are not useful for entanglement-based, one-sided device-independent, or device-independent quantum-information processing, respectively. Here, we show that such breaking channels are related to complementary tests of macrorealism, i.e., temporal separability, channel unsteerability, temporal unsteerability, and the temporal Bell inequality. To demonstrate this we first define a steerability-breaking channel, which is conceptually similar to entanglement and nonlocality-breaking channels and prove that it is identical to an incompatibility-breaking channel. A hierarchy of quantum nonbreaking channels is derived, akin to the existing hierarchy relations for temporal and spatial quantum correlations. We then introduce the concept of channels that break temporal correlations, explain how they are related to the standard breaking channels, and prove the following results. (1) A robustness-based measure for non-entanglement-breaking channels can be probed by temporal nonseparability. (2) A non-steerability-breaking channel can be quantified by channel steering. (3) Temporal steerability and nonmacrorealism can be used for, respectively, distinguishing unital steerability-breaking channels and nonlocality-breaking channels for a maximally entangled state. Finally, a two-dimensional depolarizing channel is experimentally implemented as a proof-of-principle example to demonstrate the hierarchy relation of nonbreaking channels using temporal quantum correlations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Quantum channels breaking entanglement, incompatibility, or nonlocality are defined as such because they are not useful for entanglement-based, one-sided device-independent, or device-independent quantum-information processing, respectively. Here, we show that such breaking channels are related to complementary tests of macrorealism, i.e., temporal separability, channel unsteerability, temporal unsteerability, and the temporal Bell inequality. To demonstrate this we first define a steerability-breaking channel, which is conceptually similar to entanglement and nonlocality-breaking channels and prove that it is identical to an incompatibility-breaking channel. A hierarchy of quantum nonbreaking channels is derived, akin to the existing hierarchy relations for temporal and spatial quantum correlations. We then introduce the concept of channels that break temporal correlations, explain how they are related to the standard breaking channels, and prove the following results. (1) A robustness-based measure for non-entanglement-breaking channels can be probed by temporal nonseparability. (2) A non-steerability-breaking channel can be quantified by channel steering. (3) Temporal steerability and nonmacrorealism can be used for, respectively, distinguishing unital steerability-breaking channels and nonlocality-breaking channels for a maximally entangled state. Finally, a two-dimensional depolarizing channel is experimentally implemented as a proof-of-principle example to demonstrate the hierarchy relation of nonbreaking channels using temporal quantum correlations. Close https://journals.aps.org/prxquantum/abstract/10.1103/PRXQuantum.3.020338 doi:10.1103/PRXQuantum.3.020338 Close
20.	Chia-Yi Ju, Adam Miranowicz, Fabrizio Minganti, Chuan-Tsung Chan, Guang-Yin Chen, Franco Nori Einstein's quantum elevator: Hermitization of non-Hermitian Hamiltonians via a generalized vielbein formalism Phys. Rev. Research, 4 , pp. 023070, 2022. Abstract \| Links \| BibTeX @article{Ju22prr, title = {Einstein's quantum elevator: Hermitization of non-Hermitian Hamiltonians via a generalized vielbein formalism}, author = {Chia-Yi Ju and Adam Miranowicz and Fabrizio Minganti and Chuan-Tsung Chan and Guang-Yin Chen and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.4.023070}, doi = {10.1103/PhysRevResearch.4.023070}, year = {2022}, date = {2022-04-01}, journal = {Phys. Rev. Research}, volume = {4}, pages = {023070}, publisher = {American Physical Society}, abstract = {The formalism for non-Hermitian quantum systems sometimes blurs the underlying physics. We present a systematic study of the vielbeinlike formalism which transforms the Hilbert space bundles of non-Hermitian systems into the conventional ones, rendering the induced Hamiltonian to be Hermitian. In other words, any non-Hermitian Hamiltonian can be “transformed” into a Hermitian one without altering the physics. Thus we show how to find a reference frame (corresponding to Einstein's quantum elevator) in which a non-Hermitian system, equipped with a nontrivial Hilbert space metric, reduces to a Hermitian system within the standard formalism of quantum mechanics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The formalism for non-Hermitian quantum systems sometimes blurs the underlying physics. We present a systematic study of the vielbeinlike formalism which transforms the Hilbert space bundles of non-Hermitian systems into the conventional ones, rendering the induced Hamiltonian to be Hermitian. In other words, any non-Hermitian Hamiltonian can be “transformed” into a Hermitian one without altering the physics. Thus we show how to find a reference frame (corresponding to Einstein's quantum elevator) in which a non-Hermitian system, equipped with a nontrivial Hilbert space metric, reduces to a Hermitian system within the standard formalism of quantum mechanics. Close https://link.aps.org/doi/10.1103/PhysRevResearch.4.023070 doi:10.1103/PhysRevResearch.4.023070 Close
19.	Yi-Hao Kang, Ye-Hong Chen, Xin Wang, Jie Song, Yan Xia, Adam Miranowicz, Shi-Biao Zheng, Franco Nori Nonadiabatic geometric quantum computation with cat-state qubits via invariant-based reverse engineering Phys. Rev. Research, 4 , pp. 013233, 2022. Abstract \| Links \| BibTeX @article{Kang2022, title = {Nonadiabatic geometric quantum computation with cat-state qubits via invariant-based reverse engineering}, author = {Yi-Hao Kang and Ye-Hong Chen and Xin Wang and Jie Song and Yan Xia and Adam Miranowicz and Shi-Biao Zheng and Franco Nori}, url = {https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.4.013233}, doi = {10.1103/PhysRevResearch.4.013233}, year = {2022}, date = {2022-03-28}, journal = {Phys. Rev. Research}, volume = {4}, pages = {013233}, abstract = {We propose a protocol to realize nonadiabatic geometric quantum computation of small-amplitude Schrödinger cat qubits via invariant-based reverse engineering. We consider a system with a two-photon driven Kerr nonlinearity, which can generate a pair of dressed even and odd coherent states (i.e., Schrödinger cat states) for fault-tolerant quantum computations. An additional coherent field is applied to linearly drive a cavity mode, to induce oscillations between dressed cat states. By designing this linear drive with invariant-based reverse engineering, we show how to implement nonadiabatic geometric quantum computation with cat qubits. The performance of the protocol is estimated by taking into account the influence of systematic errors, additive white Gaussian noise, 1/f noise, and decoherence including photon loss and dephasing. Numerical results demonstrate that our protocol is robust against these negative factors. Therefore, this protocol may provide a feasible method for nonadiabatic geometric quantum computation in bosonic systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose a protocol to realize nonadiabatic geometric quantum computation of small-amplitude Schrödinger cat qubits via invariant-based reverse engineering. We consider a system with a two-photon driven Kerr nonlinearity, which can generate a pair of dressed even and odd coherent states (i.e., Schrödinger cat states) for fault-tolerant quantum computations. An additional coherent field is applied to linearly drive a cavity mode, to induce oscillations between dressed cat states. By designing this linear drive with invariant-based reverse engineering, we show how to implement nonadiabatic geometric quantum computation with cat qubits. The performance of the protocol is estimated by taking into account the influence of systematic errors, additive white Gaussian noise, 1/f noise, and decoherence including photon loss and dephasing. Numerical results demonstrate that our protocol is robust against these negative factors. Therefore, this protocol may provide a feasible method for nonadiabatic geometric quantum computation in bosonic systems. Close https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.4.013233 doi:10.1103/PhysRevResearch.4.013233 Close
18.	Patrycja Tulewicz, Kacper Wrześniewski, Ireneusz Weymann Spintronic transport through a double quantum dot-based spin valve with noncollinear magnetizations Journal of Magnetism and Magnetic Materials, 546 , pp. 168788, 2022. Abstract \| Links \| BibTeX @article{Tulewicz2022, title = {Spintronic transport through a double quantum dot-based spin valve with noncollinear magnetizations}, author = {Patrycja Tulewicz and Kacper Wrześniewski and Ireneusz Weymann}, url = {https://www.sciencedirect.com/science/article/pii/S0304885321010118}, doi = {10.1016/j.jmmm.2021.168788}, year = {2022}, date = {2022-03-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {546}, pages = {168788}, abstract = {We study the magnetoresistive properties of a spin valve based on a double quantum dot attached to ferromagnetic leads with noncollinear alignment of magnetic moments. It is assumed that each dot is strongly coupled to its own ferromagnetic electrode, while the hopping between the dots is relatively weak. The calculations are performed by using the perturbation theory in the coupling between the dots, while the local density of states of a quantum dot attached to a given external lead is determined with the aid of the numerical renormalization group method. We demonstrate that the examined device can exhibit considerable positive or inverse tunnel magnetoresistance. It can be also a source of highly spin-polarized current. Importantly, the spin-resolved transport properties can be controlled by gate and bias voltages and depend on the angle between the magnetizations of the ferromagnets.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We study the magnetoresistive properties of a spin valve based on a double quantum dot attached to ferromagnetic leads with noncollinear alignment of magnetic moments. It is assumed that each dot is strongly coupled to its own ferromagnetic electrode, while the hopping between the dots is relatively weak. The calculations are performed by using the perturbation theory in the coupling between the dots, while the local density of states of a quantum dot attached to a given external lead is determined with the aid of the numerical renormalization group method. We demonstrate that the examined device can exhibit considerable positive or inverse tunnel magnetoresistance. It can be also a source of highly spin-polarized current. Importantly, the spin-resolved transport properties can be controlled by gate and bias voltages and depend on the angle between the magnetizations of the ferromagnets. Close https://www.sciencedirect.com/science/article/pii/S0304885321010118 doi:10.1016/j.jmmm.2021.168788 Close
2021
17.	Fabrizio Minganti, Ievgen I Arkhipov, Adam Miranowicz, Franco Nori Continuous dissipative phase transitions with or without symmetry breaking New Journal of Physics, 23 (12), pp. 122001, 2021. Abstract \| Links \| BibTeX @article{Minganti2021b, title = {Continuous dissipative phase transitions with or without symmetry breaking}, author = {Fabrizio Minganti and Ievgen I Arkhipov and Adam Miranowicz and Franco Nori}, url = {https://doi.org/10.1088/1367-2630/ac3db8}, doi = {10.1088/1367-2630/ac3db8}, year = {2021}, date = {2021-12-22}, journal = {New Journal of Physics}, volume = {23}, number = {12}, pages = {122001}, publisher = {IOP Publishing}, abstract = {The paradigm of second-order phase transitions (PTs) induced by spontaneous symmetry breaking (SSB) in thermal and quantum systems is a pillar of modern physics that has been fruitfully applied to out-of-equilibrium open quantum systems. Dissipative phase transitions (DPTs) of second order are often connected with SSB, in close analogy with well-known thermal second-order PTs in closed quantum and classical systems. That is, a second-order DPT should disappear by preventing the occurrence of SSB. Here, we prove this statement to be wrong, showing that, surprisingly, SSB is not a necessary condition for the occurrence of second-order DPTs in out-of-equilibrium open quantum systems. We analytically prove this result using the Liouvillian theory of DPTs, and demonstrate this anomalous transition in a paradigmatic laser model, where we can arbitrarily remove SSB while retaining criticality, and on a Z2-symmetric model of a two-photon Kerr resonator. This new type of PT cannot be interpreted as a ‘semiclassical’ bifurcation, because, after the DPT, the system steady state remains unique.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The paradigm of second-order phase transitions (PTs) induced by spontaneous symmetry breaking (SSB) in thermal and quantum systems is a pillar of modern physics that has been fruitfully applied to out-of-equilibrium open quantum systems. Dissipative phase transitions (DPTs) of second order are often connected with SSB, in close analogy with well-known thermal second-order PTs in closed quantum and classical systems. That is, a second-order DPT should disappear by preventing the occurrence of SSB. Here, we prove this statement to be wrong, showing that, surprisingly, SSB is not a necessary condition for the occurrence of second-order DPTs in out-of-equilibrium open quantum systems. We analytically prove this result using the Liouvillian theory of DPTs, and demonstrate this anomalous transition in a paradigmatic laser model, where we can arbitrarily remove SSB while retaining criticality, and on a Z2-symmetric model of a two-photon Kerr resonator. This new type of PT cannot be interpreted as a ‘semiclassical’ bifurcation, because, after the DPT, the system steady state remains unique. Close https://doi.org/10.1088/1367-2630/ac3db8 doi:10.1088/1367-2630/ac3db8 Close
16.	Fabrizio Minganti, Ievgen I Arkhipov, Adam Miranowicz, Franco Nori Liouvillian spectral collapse in the Scully-Lamb laser model Physical Review Research, 3 (4), pp. 043197, 2021. Abstract \| Links \| BibTeX @article{Minganti2021, title = {Liouvillian spectral collapse in the Scully-Lamb laser model}, author = {Fabrizio Minganti and Ievgen I Arkhipov and Adam Miranowicz and Franco Nori}, url = {https://doi.org/10.1103/physrevresearch.3.043197}, doi = {10.1103/physrevresearch.3.043197}, year = {2021}, date = {2021-12-21}, journal = {Physical Review Research}, volume = {3}, number = {4}, pages = {043197}, publisher = {American Physical Society (APS)}, abstract = {Phase transitions of thermal systems and the laser threshold were first connected more than forty years ago. Despite the nonequilibrium nature of the laser, the Landau theory of thermal phase transitions, applied directly to the Scully-Lamb laser model (SLLM), indicates that the laser threshold is a second-order phase transition, associated with a U(1) spontaneous symmetry breaking (SSB). To capture the genuine nonequilibrium phase transition of the SLLM (i.e., a single-mode laser without a saturable absorber), here we employ a quantum theory of dissipative phase transitions. Our results confirm that the U(1) SSB can occur at the lasing threshold but, in contrast to the Landau theory and semiclassical approximation, they signal that the SLLM “fundamental” transition is a different phenomenon, which we call Liouvillian spectral collapse; that is, the emergence of diabolic points of infinite degeneracy. By considering a generalized SLLM with additional dephasing, we witness a second-order phase transition, with a Liouvillian spectral collapse, but in the absence of symmetry breaking. Most surprisingly, the phase transition corresponds to the emergence of dynamical multistability even without SSB. Normally, bistability is suppressed by quantum fluctuations, while in this case, the very presence of quantum fluctuations enables bistability. This rather anomalous bistability, characterizing the truly dissipative and quantum origin of lasing, can be an experimental signature of our predictions, and we show that it is associated with an emergent dynamical hysteresis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Phase transitions of thermal systems and the laser threshold were first connected more than forty years ago. Despite the nonequilibrium nature of the laser, the Landau theory of thermal phase transitions, applied directly to the Scully-Lamb laser model (SLLM), indicates that the laser threshold is a second-order phase transition, associated with a U(1) spontaneous symmetry breaking (SSB). To capture the genuine nonequilibrium phase transition of the SLLM (i.e., a single-mode laser without a saturable absorber), here we employ a quantum theory of dissipative phase transitions. Our results confirm that the U(1) SSB can occur at the lasing threshold but, in contrast to the Landau theory and semiclassical approximation, they signal that the SLLM “fundamental” transition is a different phenomenon, which we call Liouvillian spectral collapse; that is, the emergence of diabolic points of infinite degeneracy. By considering a generalized SLLM with additional dephasing, we witness a second-order phase transition, with a Liouvillian spectral collapse, but in the absence of symmetry breaking. Most surprisingly, the phase transition corresponds to the emergence of dynamical multistability even without SSB. Normally, bistability is suppressed by quantum fluctuations, while in this case, the very presence of quantum fluctuations enables bistability. This rather anomalous bistability, characterizing the truly dissipative and quantum origin of lasing, can be an experimental signature of our predictions, and we show that it is associated with an emergent dynamical hysteresis. Close https://doi.org/10.1103/physrevresearch.3.043197 doi:10.1103/physrevresearch.3.043197 Close
15.	Kateřina Jirákov á, Antonín Č, Karel Lemr, Karol Bartkiewicz, Adam Miranowicz Experimental hierarchy and optimal robustness of quantum correlations of two-qubit states with controllable white noise Physical Review A, 104 (6), pp. 062436, 2021. Abstract \| Links \| BibTeX @article{Jirakova2021b, title = {Experimental hierarchy and optimal robustness of quantum correlations of two-qubit states with controllable white noise}, author = {Kate{ř}ina Jirákov á and Antonín Č and Karel Lemr and Karol Bartkiewicz and Adam Miranowicz}, url = {https://doi.org/10.1103/physreva.104.062436}, doi = {10.1103/physreva.104.062436}, year = {2021}, date = {2021-12-21}, journal = {Physical Review A}, volume = {104}, number = {6}, pages = {062436}, publisher = {American Physical Society (APS)}, abstract = {We demonstrate a hierarchy of various classes of quantum correlations on experimentally prepared two-qubit Werner-like states with controllable white noise. Werner states, which are white-noise-affected Bell states, are prototypal examples for studying such a hierarchy as a function of the amount of white noise. We experimentally generate Werner states and their generalizations, i.e., partially entangled pure states affected by white noise. These states enable us to study the hierarchy of the following classes of correlations: separability, entanglement, steering in three- and two-measurement scenarios, and Bell nonlocality. We show that the generalized Werner states (GWSs) reveal fundamentally different aspects of the hierarchy compared to the Werner states. In particular, we find five different parameter regimes of the GWSs, including those steerable in a two-measurement scenario but not violating Bell inequalities. This regime cannot be observed for the usual Werner states. Moreover, we find threshold curves separating different regimes of the quantum correlations and find the optimal states which allow for the largest amount of white noise which does not destroy their specific quantum correlations (e.g., unsteerable entanglement). Thus, we could identify the optimal Bell-nondiagonal GWSs which are, for this specific meaning, more robust against the white noise compared to the Bell-diagonal GWSs (i.e., Werner states).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We demonstrate a hierarchy of various classes of quantum correlations on experimentally prepared two-qubit Werner-like states with controllable white noise. Werner states, which are white-noise-affected Bell states, are prototypal examples for studying such a hierarchy as a function of the amount of white noise. We experimentally generate Werner states and their generalizations, i.e., partially entangled pure states affected by white noise. These states enable us to study the hierarchy of the following classes of correlations: separability, entanglement, steering in three- and two-measurement scenarios, and Bell nonlocality. We show that the generalized Werner states (GWSs) reveal fundamentally different aspects of the hierarchy compared to the Werner states. In particular, we find five different parameter regimes of the GWSs, including those steerable in a two-measurement scenario but not violating Bell inequalities. This regime cannot be observed for the usual Werner states. Moreover, we find threshold curves separating different regimes of the quantum correlations and find the optimal states which allow for the largest amount of white noise which does not destroy their specific quantum correlations (e.g., unsteerable entanglement). Thus, we could identify the optimal Bell-nondiagonal GWSs which are, for this specific meaning, more robust against the white noise compared to the Bell-diagonal GWSs (i.e., Werner states). Close https://doi.org/10.1103/physreva.104.062436 doi:10.1103/physreva.104.062436 Close
14.	Andrzej Grudka, Paweł Kurzyński, Antoni Wójcik Quantum semipermeable barriers: Investigating Maxwell's demon toolbox Physical Review E, 104 , pp. 064114, 2021. Abstract \| Links \| BibTeX @article{Grudka2021, title = {Quantum semipermeable barriers: Investigating Maxwell's demon toolbox}, author = {Andrzej Grudka and Paweł Kurzyński and Antoni Wójcik}, url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.104.064114}, doi = {10.1103/PhysRevE.104.064114}, year = {2021}, date = {2021-12-10}, journal = {Physical Review E}, volume = {104}, pages = {064114}, abstract = {We study quantum Maxwell's demon in a discrete space-time setup. We consider a collection of particles hopping on a one-dimensional chain and a semipermeable barrier that allows the particles to hop in only one direction. Our main result is a formulation of a local unitary dynamics describing the action of this barrier. Such dynamics utilizes an auxiliary system A and we study how properties of A influence the behavior of particles. An immediate consequence of unitarity is the fact that particles cannot be trapped on one side of the barrier forever, unless A is infinite. In addition, coherent superpositions and quantum correlations are affected once particles enter the confinement region. Finally, we show that initial superposition of A allows the barrier to act as a beam splitter.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We study quantum Maxwell's demon in a discrete space-time setup. We consider a collection of particles hopping on a one-dimensional chain and a semipermeable barrier that allows the particles to hop in only one direction. Our main result is a formulation of a local unitary dynamics describing the action of this barrier. Such dynamics utilizes an auxiliary system A and we study how properties of A influence the behavior of particles. An immediate consequence of unitarity is the fact that particles cannot be trapped on one side of the barrier forever, unless A is infinite. In addition, coherent superpositions and quantum correlations are affected once particles enter the confinement region. Finally, we show that initial superposition of A allows the barrier to act as a beam splitter. Close https://journals.aps.org/pre/abstract/10.1103/PhysRevE.104.064114 doi:10.1103/PhysRevE.104.064114 Close
13.	Paweł Kurzyński Weighted Bures length uncovers quantum state sensitivity Physical Review E, 104 , pp. L052202, 2021. Abstract \| Links \| BibTeX @article{Kurzyński2021, title = {Weighted Bures length uncovers quantum state sensitivity}, author = {Paweł Kurzyński}, url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.104.L052202}, doi = {10.1103/PhysRevE.104.L052202}, year = {2021}, date = {2021-11-18}, journal = {Physical Review E}, volume = {104}, pages = {L052202}, abstract = {The unitarity of quantum evolutions implies that an overlap between two initial states does not change in time. This property is commonly believed to explain the apparent lack of state sensitivity in quantum theory, a feature that is prevailing in classical chaotic systems. However, classical state sensitivity is based on a distance between two trajectories in phase space which is a completely different mathematical concept than an overlap between two vectors in Hilbert space. It is possible that state sensitivity in quantum theory can be detected with the help of some special metric. Here we show that the recently introduced Weighted Bures length achieves this task. We numerically investigate a unitary cellular automaton of N interacting qubits and analyze how a single-qubit perturbation affects the evolution of WBL between the unperturbed and perturbed states. We observe a linear growth of WBL if the qubits are arranged into a cyclic graph and an exponential growth if they are arranged into a random bipartite graph.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The unitarity of quantum evolutions implies that an overlap between two initial states does not change in time. This property is commonly believed to explain the apparent lack of state sensitivity in quantum theory, a feature that is prevailing in classical chaotic systems. However, classical state sensitivity is based on a distance between two trajectories in phase space which is a completely different mathematical concept than an overlap between two vectors in Hilbert space. It is possible that state sensitivity in quantum theory can be detected with the help of some special metric. Here we show that the recently introduced Weighted Bures length achieves this task. We numerically investigate a unitary cellular automaton of N interacting qubits and analyze how a single-qubit perturbation affects the evolution of WBL between the unperturbed and perturbed states. We observe a linear growth of WBL if the qubits are arranged into a cyclic graph and an exponential growth if they are arranged into a random bipartite graph. Close https://journals.aps.org/pre/abstract/10.1103/PhysRevE.104.L052202 doi:10.1103/PhysRevE.104.L052202 Close
12.	Hai Xu, Deng-Gao Lai, Yi-Bing Qian, Bang-Pin Hou, Adam Miranowicz, Franco Nori Optomechanical dynamics in the PT- and broken-PT-symmetric regimes Physical Review A, 104 (5), pp. 053518, 2021. Abstract \| Links \| BibTeX @article{Xu2021, title = {Optomechanical dynamics in the PT- and broken-PT-symmetric regimes}, author = {Hai Xu and Deng-Gao Lai and Yi-Bing Qian and Bang-Pin Hou and Adam Miranowicz and Franco Nori}, url = {https://doi.org/10.1103/physreva.104.053518}, doi = {10.1103/physreva.104.053518}, year = {2021}, date = {2021-11-04}, journal = {Physical Review A}, volume = {104}, number = {5}, pages = {053518}, publisher = {American Physical Society (APS)}, abstract = {We theoretically study the dynamics of an optomechanical system, consisting of a passive optical mode and an active mechanical mode, in the PT- and broken-PT-symmetric regimes. By fully analytical treatments for the dynamics of the average displacement and particle numbers, we reveal the phase diagram under different conditions and the various regimes of both PT symmetry and stability of the system. We find that by appropriately tuning either mechanical gain or optomechanical coupling, both phase transitions of the PT symmetry and stability of the system can be flexibly controlled. As a result, the dynamical behaviors of the average displacement, photons, and phonons are radically changed in different regimes. The presented physical mechanism is general and this method can be extended to a general model of dissipative and amplified coupled systems. Our study shows that PT-symmetric optomechanical devices can serve as a powerful tool for the manipulation of mechanical motion, photons, and phonons.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We theoretically study the dynamics of an optomechanical system, consisting of a passive optical mode and an active mechanical mode, in the PT- and broken-PT-symmetric regimes. By fully analytical treatments for the dynamics of the average displacement and particle numbers, we reveal the phase diagram under different conditions and the various regimes of both PT symmetry and stability of the system. We find that by appropriately tuning either mechanical gain or optomechanical coupling, both phase transitions of the PT symmetry and stability of the system can be flexibly controlled. As a result, the dynamical behaviors of the average displacement, photons, and phonons are radically changed in different regimes. The presented physical mechanism is general and this method can be extended to a general model of dissipative and amplified coupled systems. Our study shows that PT-symmetric optomechanical devices can serve as a powerful tool for the manipulation of mechanical motion, photons, and phonons. Close https://doi.org/10.1103/physreva.104.053518 doi:10.1103/physreva.104.053518 Close
11.	Ying Li, Ya-Feng Jiao, Jing-Xue Liu, Adam Miranowicz, Yun-Lan Zuo, Le-Man Kuang, Hui Jing Vector optomechanical entanglement Nanophotonics, 11 (1), pp. 67–77, 2021. Abstract \| Links \| BibTeX @article{Li2021, title = {Vector optomechanical entanglement}, author = {Ying Li and Ya-Feng Jiao and Jing-Xue Liu and Adam Miranowicz and Yun-Lan Zuo and Le-Man Kuang and Hui Jing}, url = {https://doi.org/10.1515/nanoph-2021-0485}, doi = {10.1515/nanoph-2021-0485}, year = {2021}, date = {2021-11-02}, journal = {Nanophotonics}, volume = {11}, number = {1}, pages = {67--77}, abstract = {The polarizations of optical fields, besides field intensities, provide more degrees of freedom to manipulate coherent light–matter interactions. Here, we propose how to achieve a coherent switch of optomechanical entanglement in a polarized-light-driven cavity system. We show that by tuning the polarizations of the driving field, the effective optomechanical coupling can be well controlled and, as a result, quantum entanglement between the mechanical oscillator and the optical transverse electric mode can be coherently and reversibly switched to that between the same phonon mode and the optical transverse magnetic mode. This ability to switch optomechanical entanglement with such a vectorial device can be important for building a quantum network being capable of efficient quantum information interchanges between processing nodes and flying photons.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The polarizations of optical fields, besides field intensities, provide more degrees of freedom to manipulate coherent light–matter interactions. Here, we propose how to achieve a coherent switch of optomechanical entanglement in a polarized-light-driven cavity system. We show that by tuning the polarizations of the driving field, the effective optomechanical coupling can be well controlled and, as a result, quantum entanglement between the mechanical oscillator and the optical transverse electric mode can be coherently and reversibly switched to that between the same phonon mode and the optical transverse magnetic mode. This ability to switch optomechanical entanglement with such a vectorial device can be important for building a quantum network being capable of efficient quantum information interchanges between processing nodes and flying photons. Close https://doi.org/10.1515/nanoph-2021-0485 doi:10.1515/nanoph-2021-0485 Close

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Publications by Department of Nonlinear Optics

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