List of publications

Department of Mesoscopic Physics
Department of Nonlinear Optics
Department of Physics of Nanostructures
Department of Theory of Condensed Matter

172 entries « ‹ 2 of 4 › »

2022
122.	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
121.	Konrad J. Kapcia, V. Tkachenko, F. Capotondi, A. Lichtenstein, S. Molodtsov, L. Müller, A. Philippi-Kobs, P. Piekarz, B. Ziaja Modeling of ultrafast X-ray induced magnetization dynamics in magnetic multilayer systems npj Computational Materials, 8 , pp. 212, 2022. Abstract \| Links \| BibTeX @article{Kapcia2022, title = {Modeling of ultrafast X-ray induced magnetization dynamics in magnetic multilayer systems}, author = {Konrad J. Kapcia and V. Tkachenko and F. Capotondi and A. Lichtenstein and S. Molodtsov and L. Müller and A. Philippi-Kobs and P. Piekarz and B. Ziaja}, url = {https://www.nature.com/articles/s41524-022-00895-4}, doi = {10.1038/s41524-022-00895-4}, year = {2022}, date = {2022-10-01}, journal = {npj Computational Materials}, volume = {8}, pages = {212}, abstract = {In this work, we report on modeling results obtained with our recently developed simulation tool enabling nanoscopic description of electronic processes in X-ray irradiated ferromagnetic materials. With this tool, we have studied the response of Co/Pt multilayer system irradiated by an ultrafast extreme ultraviolet pulse at the M-edge of Co (photon energy ~60 eV). It was previously investigated experimentally at the FERMI free-electron-laser facility, using the magnetic small-angle X-ray scattering technique. Our simulations show that the magnetic scattering signal from cobalt decreases on femtosecond timescales due to electronic excitation, relaxation, and transport processes both in the cobalt and in the platinum layers, following the trend observed in the experimental data. The confirmation of the predominant role of electronic processes for X-ray induced demagnetization in the regime below the structural damage threshold is a step toward quantitative control and manipulation of X-ray induced magnetic processes on femtosecond timescales.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close In this work, we report on modeling results obtained with our recently developed simulation tool enabling nanoscopic description of electronic processes in X-ray irradiated ferromagnetic materials. With this tool, we have studied the response of Co/Pt multilayer system irradiated by an ultrafast extreme ultraviolet pulse at the M-edge of Co (photon energy ~60 eV). It was previously investigated experimentally at the FERMI free-electron-laser facility, using the magnetic small-angle X-ray scattering technique. Our simulations show that the magnetic scattering signal from cobalt decreases on femtosecond timescales due to electronic excitation, relaxation, and transport processes both in the cobalt and in the platinum layers, following the trend observed in the experimental data. The confirmation of the predominant role of electronic processes for X-ray induced demagnetization in the regime below the structural damage threshold is a step toward quantitative control and manipulation of X-ray induced magnetic processes on femtosecond timescales. Close https://www.nature.com/articles/s41524-022-00895-4 doi:10.1038/s41524-022-00895-4 Close
120.	Tomoyuki Yokouchi, Satoshi Sugimoto, Bivas Rana, Shinichiro Seki, Naoki Ogawa, Yuki Shiomi, Shinya Kasai, Yoshichika Otani Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions Science Advances, 8 (39), pp. eabq5652, 2022. Abstract \| Links \| BibTeX @article{doi:10.1126/sciadv.abq5652, title = {Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions}, author = {Tomoyuki Yokouchi and Satoshi Sugimoto and Bivas Rana and Shinichiro Seki and Naoki Ogawa and Yuki Shiomi and Shinya Kasai and Yoshichika Otani}, url = {https://www.science.org/doi/pdf/10.1126/sciadv.abq5652}, doi = {10.1126/sciadv.abq5652}, year = {2022}, date = {2022-09-30}, journal = {Science Advances}, volume = {8}, number = {39}, pages = {eabq5652}, abstract = {Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field–induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices. Skyrmion-based neuromorphic computing device recognizes waveforms and handwritten digits with high accuracy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field–induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices. Skyrmion-based neuromorphic computing device recognizes waveforms and handwritten digits with high accuracy. Close https://www.science.org/doi/pdf/10.1126/sciadv.abq5652 doi:10.1126/sciadv.abq5652 Close
119.	Miłosz Rybak, Tomasz Woźniak, Magdalena Birowska, Filip Dybała, Alfredo Segura, Konrad J. Kapcia, Paweł Scharoch, Robert Kudrawiec Stress-Tuned Optical Transitions in Layered 1T-MX2 (M=Hf, Zr, Sn; X=S, Se) Crystals Nanomaterials, 12 (19), pp. 3433, 2022. Abstract \| Links \| BibTeX @article{Rybak2022, title = {Stress-Tuned Optical Transitions in Layered 1T-MX2 (M=Hf, Zr, Sn; X=S, Se) Crystals }, author = {Miłosz Rybak and Tomasz Woźniak and Magdalena Birowska and Filip Dybała and Alfredo Segura and Konrad J. Kapcia and Paweł Scharoch and Robert Kudrawiec}, url = {https://www.mdpi.com/2079-4991/12/19/3433}, doi = {10.3390/nano12193433}, year = {2022}, date = {2022-09-30}, journal = {Nanomaterials}, volume = {12}, number = {19}, pages = {3433}, abstract = {Optical measurements under externally applied stresses allow us to study the materials’ electronic structure by comparing the pressure evolution of optical peaks obtained from experiments and theoretical calculations. We examine the stress-induced changes in electronic structure for the thermodynamically stable 1T polytype of selected MX2 compounds (M=Hf, Zr, Sn; X=S, Se), using the density functional theory. We demonstrate that considered 1T-MX2 materials are semiconducting with indirect character of the band gap, irrespective to the employed pressure as predicted using modified Becke–Johnson potential. We determine energies of direct interband transitions between bands extrema and in band-nesting regions close to Fermi level. Generally, the studied transitions are optically active, exhibiting in-plane polarization of light. Finally, we quantify their energy trends under external hydrostatic, uniaxial, and biaxial stresses by determining the linear pressure coefficients. Generally, negative pressure coefficients are obtained implying the narrowing of the band gap. The semiconducting-to-metal transition are predicted under hydrostatic pressure. We discuss these trends in terms of orbital composition of involved electronic bands. In addition, we demonstrate that the measured pressure coefficients of HfS2 and HfSe2 absorption edges are in perfect agreement with our predictions. Comprehensive and easy-to-interpret tables containing the optical features are provided to form the basis for assignation of optical peaks in future measurements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Optical measurements under externally applied stresses allow us to study the materials’ electronic structure by comparing the pressure evolution of optical peaks obtained from experiments and theoretical calculations. We examine the stress-induced changes in electronic structure for the thermodynamically stable 1T polytype of selected MX2 compounds (M=Hf, Zr, Sn; X=S, Se), using the density functional theory. We demonstrate that considered 1T-MX2 materials are semiconducting with indirect character of the band gap, irrespective to the employed pressure as predicted using modified Becke–Johnson potential. We determine energies of direct interband transitions between bands extrema and in band-nesting regions close to Fermi level. Generally, the studied transitions are optically active, exhibiting in-plane polarization of light. Finally, we quantify their energy trends under external hydrostatic, uniaxial, and biaxial stresses by determining the linear pressure coefficients. Generally, negative pressure coefficients are obtained implying the narrowing of the band gap. The semiconducting-to-metal transition are predicted under hydrostatic pressure. We discuss these trends in terms of orbital composition of involved electronic bands. In addition, we demonstrate that the measured pressure coefficients of HfS2 and HfSe2 absorption edges are in perfect agreement with our predictions. Comprehensive and easy-to-interpret tables containing the optical features are provided to form the basis for assignation of optical peaks in future measurements. Close https://www.mdpi.com/2079-4991/12/19/3433 doi:10.3390/nano12193433 Close
118.	X.-G. Wang, L. Chotorlishvili, G. Tatara, Anna Dyrdał, Guang-hua Guo, V. K. Dugaev, Józef Barnaś, S.S.P. Parkin, A. Ernst Skyrmion lattice hosted in synthetic antiferromagnets and helix modes Phys. Rev. B, 106 , pp. 104424, 2022. Abstract \| Links \| BibTeX @article{Wang2022b, title = {Skyrmion lattice hosted in synthetic antiferromagnets and helix modes}, author = {X.-G. Wang and L. Chotorlishvili and G. Tatara and Anna Dyrdał and Guang-hua Guo and V. K. Dugaev and Józef Barnaś and S.S.P. Parkin and A. Ernst}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.104424}, doi = {10.1103/PhysRevB.106.104424}, year = {2022}, date = {2022-09-20}, journal = {Phys. Rev. B}, volume = {106}, pages = {104424}, abstract = {Thin ferromagnetic films can possess unconventional magnetic properties, opening a new road for using them in spintronic technologies. In the present work exploiting three different methods, we comprehensively analyze phason excitations of a skyrmion lattice in synthetic antiferromagnets. To analyze phason excitations of the skyrmion lattice, we have constructed an analytical model based on three coupled helices and found a linear gapless mode. Micromagnetic simulations also support this result. Moreover, a similar result has been achieved within the rigid skyrmion lattice model based on the coupled Thiele's equations, when the coupling between skyrmions in different layers of the synthetic antiferromagnetic is comparable to or larger than the intralayer coupling. In addition, we also consider the orbital angular momentum and spin pumping current associated with phason excitations. Due to the gapless excitations in the case of skyrmion lattice, the pumping current is nonzero for the arbitrary frequency of pumping microwaves. In the case of individual skyrmions, no current is pumped when microwave frequency is inside the gap of the spectrum of individual skyrmions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Thin ferromagnetic films can possess unconventional magnetic properties, opening a new road for using them in spintronic technologies. In the present work exploiting three different methods, we comprehensively analyze phason excitations of a skyrmion lattice in synthetic antiferromagnets. To analyze phason excitations of the skyrmion lattice, we have constructed an analytical model based on three coupled helices and found a linear gapless mode. Micromagnetic simulations also support this result. Moreover, a similar result has been achieved within the rigid skyrmion lattice model based on the coupled Thiele's equations, when the coupling between skyrmions in different layers of the synthetic antiferromagnetic is comparable to or larger than the intralayer coupling. In addition, we also consider the orbital angular momentum and spin pumping current associated with phason excitations. Due to the gapless excitations in the case of skyrmion lattice, the pumping current is nonzero for the arbitrary frequency of pumping microwaves. In the case of individual skyrmions, no current is pumped when microwave frequency is inside the gap of the spectrum of individual skyrmions. Close https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.104424 doi:10.1103/PhysRevB.106.104424 Close
117.	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
116.	Anand Manaparambil, Andreas Weichselbaum, Jan von Delft, Ireneusz Weymann Nonequilibrium spintronic transport through Kondo impurities Phys. Rev. B, 106 , pp. 125413, 2022. Abstract \| Links \| BibTeX @article{Manaparambil2022, title = {Nonequilibrium spintronic transport through Kondo impurities}, author = {Anand Manaparambil and Andreas Weichselbaum and Jan von Delft and Ireneusz Weymann}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.125413}, doi = {10.1103/PhysRevB.106.125413}, year = {2022}, date = {2022-09-14}, journal = {Phys. Rev. B}, volume = {106}, pages = {125413}, abstract = {In this work we analyze the nonequilibrium transport through a quantum impurity (quantum dot or molecule) attached to ferromagnetic leads by using a hybrid numerical renormalization group–time-dependent density matrix renormalization group thermofield quench approach. For this, we study the bias dependence of the differential conductance through the system, which shows a finite zero-bias peak, characteristic of the Kondo resonance and reminiscent of the equilibrium local density of states. In the nonequilibrium settings, the resonance in the differential conductance is also found to decrease with increasing the lead spin polarization. The latter induces an effective exchange field that lifts the spin degeneracy of the dot level. Therefore, as we demonstrate, the Kondo resonance can be restored by counteracting the exchange field with a finite external magnetic field applied to the system. Finally, we investigate the influence of temperature on the nonequilibrium conductance, focusing on the split Kondo resonance. Our work thus provides an accurate quantitative description of the spin-resolved transport properties relevant for quantum dots and molecules embedded in magnetic tunnel junctions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close In this work we analyze the nonequilibrium transport through a quantum impurity (quantum dot or molecule) attached to ferromagnetic leads by using a hybrid numerical renormalization group–time-dependent density matrix renormalization group thermofield quench approach. For this, we study the bias dependence of the differential conductance through the system, which shows a finite zero-bias peak, characteristic of the Kondo resonance and reminiscent of the equilibrium local density of states. In the nonequilibrium settings, the resonance in the differential conductance is also found to decrease with increasing the lead spin polarization. The latter induces an effective exchange field that lifts the spin degeneracy of the dot level. Therefore, as we demonstrate, the Kondo resonance can be restored by counteracting the exchange field with a finite external magnetic field applied to the system. Finally, we investigate the influence of temperature on the nonequilibrium conductance, focusing on the split Kondo resonance. Our work thus provides an accurate quantitative description of the spin-resolved transport properties relevant for quantum dots and molecules embedded in magnetic tunnel junctions. Close https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.125413 doi:10.1103/PhysRevB.106.125413 Close
115.	X.-G. Wang, Guang-hua Guo, Anna Dyrdał, Józef Barnaś, V. K. Dugaev, S. S. P. Parkin, A. Ernst, L. Chotorlishvili Skyrmion Echo in a System of Interacting Skyrmions Phys. Rev. Lett., 129 , pp. 126101, 2022. Abstract \| Links \| BibTeX @article{Wang2022, title = {Skyrmion Echo in a System of Interacting Skyrmions}, author = {X.-G. Wang and Guang-hua Guo and Anna Dyrdał and Józef Barnaś and V. K. Dugaev and S. S. P. Parkin and A. Ernst and L. Chotorlishvili}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.126101}, doi = {10.1103/PhysRevLett.129.126101}, year = {2022}, date = {2022-09-14}, journal = {Phys. Rev. Lett.}, volume = {129}, pages = {126101}, abstract = {We consider helical rotation of skyrmions confined in the potentials formed by nanodisks. Based on numerical and analytical calculations we propose the skyrmion echo phenomenon. The physical mechanism of the skyrmion echo formation is also proposed. Because of the distortion of the lattice, impurities, or pinning effect, confined skyrmions experience slightly different local fields, which leads to dephasing of the initial signal. The interaction between skyrmions also can contribute to the dephasing process. However, switching the magnetization direction in the nanodiscs (e.g., by spin transfer torque) also switches the helical rotation of the skyrmions from clockwise to anticlockwise (or vice versa), and this restores the initial signal (which is the essence of skyrmion echo).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We consider helical rotation of skyrmions confined in the potentials formed by nanodisks. Based on numerical and analytical calculations we propose the skyrmion echo phenomenon. The physical mechanism of the skyrmion echo formation is also proposed. Because of the distortion of the lattice, impurities, or pinning effect, confined skyrmions experience slightly different local fields, which leads to dephasing of the initial signal. The interaction between skyrmions also can contribute to the dephasing process. However, switching the magnetization direction in the nanodiscs (e.g., by spin transfer torque) also switches the helical rotation of the skyrmions from clockwise to anticlockwise (or vice versa), and this restores the initial signal (which is the essence of skyrmion echo). Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.126101 doi:10.1103/PhysRevLett.129.126101 Close
114.	C. Lagoin, U. Bhattacharya, T. Grass, Ravindra W. Chhajlany, T. Salamon, K. Baldwin, L. Pfeiffer, M. Lewenstein, M. Holzmann, F. Dubin Extended Bose–Hubbard model with dipolar excitons Nature, 609 , pp. 485–489, 2022. Abstract \| Links \| BibTeX @article{Lagoin2022, title = {Extended Bose–Hubbard model with dipolar excitons}, author = {C. Lagoin and U. Bhattacharya and T. Grass and Ravindra W. Chhajlany and T. Salamon and K. Baldwin and L. Pfeiffer and M. Lewenstein and M. Holzmann and F. Dubin}, url = {https://www.nature.com/articles/s41586-022-05123-z}, doi = {10.1038/s41586-022-05123-z}, year = {2022}, date = {2022-09-14}, journal = {Nature}, volume = {609}, pages = {485–489}, abstract = {The Hubbard model constitutes one of the most celebrated theoretical frameworks of condensed-matter physics. It describes strongly correlated phases of interacting quantum particles confined in lattice potentials. For bosons, the Hubbard Hamiltonian has been deeply scrutinized for short-range on-site interactions. However, accessing longer-range couplings has remained elusive experimentally. This marks the frontier towards the extended Bose–Hubbard Hamiltonian, which enables insulating ordered phases at fractional lattice fillings. Here we implement this Hamiltonian by confining semiconductor dipolar excitons in an artificial two-dimensional square lattice. Strong dipolar repulsions between nearest-neighbour lattice sites then stabilize an insulating state at half filling. This characteristic feature of the extended Bose–Hubbard model exhibits the signatures theoretically expected for a chequerboard spatial order. Our work thus highlights that dipolar excitons enable controlled implementations of boson-like arrays with strong off-site interactions, in lattices with programmable geometries and more than 100 sites.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The Hubbard model constitutes one of the most celebrated theoretical frameworks of condensed-matter physics. It describes strongly correlated phases of interacting quantum particles confined in lattice potentials. For bosons, the Hubbard Hamiltonian has been deeply scrutinized for short-range on-site interactions. However, accessing longer-range couplings has remained elusive experimentally. This marks the frontier towards the extended Bose–Hubbard Hamiltonian, which enables insulating ordered phases at fractional lattice fillings. Here we implement this Hamiltonian by confining semiconductor dipolar excitons in an artificial two-dimensional square lattice. Strong dipolar repulsions between nearest-neighbour lattice sites then stabilize an insulating state at half filling. This characteristic feature of the extended Bose–Hubbard model exhibits the signatures theoretically expected for a chequerboard spatial order. Our work thus highlights that dipolar excitons enable controlled implementations of boson-like arrays with strong off-site interactions, in lattices with programmable geometries and more than 100 sites. Close https://www.nature.com/articles/s41586-022-05123-z doi:10.1038/s41586-022-05123-z Close
113.	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
112.	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
111.	Katarzyna Kotus, Mathieu Moalic, Mateusz Zelent, Maciej Krawczyk, Paweł Gruszecki Scattering of spin waves in a multimode waveguide under the influence of confined magnetic skyrmion APL Materials, 10 (9), pp. 091101, 2022. Abstract \| Links \| BibTeX @article{doi:10.1063/5.0100594, title = {Scattering of spin waves in a multimode waveguide under the influence of confined magnetic skyrmion}, author = {Katarzyna Kotus and Mathieu Moalic and Mateusz Zelent and Maciej Krawczyk and Paweł Gruszecki}, url = {https://doi.org/10.1063/5.0100594}, doi = {10.1063/5.0100594}, year = {2022}, date = {2022-09-08}, journal = {APL Materials}, volume = {10}, number = {9}, pages = {091101}, abstract = {Nontrivial magnetization textures, such as skyrmions, have become a driving force in the physics of magnetism. Furthermore, the utilization of magnetization textures is fueling the development of magnon-based technologies that could provide beyond-CMOS solutions. Here, using a self-developed spin wave (SW) excitation scheme, we selectively excite specific modes and investigate the scattering of SWs on nanodot hosting a Néel-type skyrmion and placed above a multimode waveguide. In particular, at low frequencies, we observe significant reflections from the imprint induced by the skyrmion upon the waveguide. As the frequency increases, the transmission increases as well; however, it is accompanied by scattering to other types of modes. Here, we observe a direct contribution of the skyrmion to the scattering process and various types of conversions of the incident SW modes into other modes quantized by width for both reflected and transmitted SWs. The utilization of imprinted magnetization textures in nonplanar systems to control SW flow can open new possibilities for developing SW-based circuits for ultralow-power signal processing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Nontrivial magnetization textures, such as skyrmions, have become a driving force in the physics of magnetism. Furthermore, the utilization of magnetization textures is fueling the development of magnon-based technologies that could provide beyond-CMOS solutions. Here, using a self-developed spin wave (SW) excitation scheme, we selectively excite specific modes and investigate the scattering of SWs on nanodot hosting a Néel-type skyrmion and placed above a multimode waveguide. In particular, at low frequencies, we observe significant reflections from the imprint induced by the skyrmion upon the waveguide. As the frequency increases, the transmission increases as well; however, it is accompanied by scattering to other types of modes. Here, we observe a direct contribution of the skyrmion to the scattering process and various types of conversions of the incident SW modes into other modes quantized by width for both reflected and transmitted SWs. The utilization of imprinted magnetization textures in nonplanar systems to control SW flow can open new possibilities for developing SW-based circuits for ultralow-power signal processing. Close https://doi.org/10.1063/5.0100594 doi:10.1063/5.0100594 Close
110.	Krzysztof Sobucki, Maciej Krawczyk, Elena V. Tartakovskaya, Piotr Graczyk Magnon spectrum of Bloch hopfion beyond ferromagnetic resonance APL Materials, 10 (9), pp. 091103, 2022. Abstract \| Links \| BibTeX @article{doi:10.1063/5.0100484, title = {Magnon spectrum of Bloch hopfion beyond ferromagnetic resonance}, author = {Krzysztof Sobucki and Maciej Krawczyk and Elena V. Tartakovskaya and Piotr Graczyk}, url = {https://doi.org/10.1063/5.0100484}, doi = {10.1063/5.0100484}, year = {2022}, date = {2022-09-08}, journal = {APL Materials}, volume = {10}, number = {9}, pages = {091103}, abstract = {With the development of new nanofabrication technologies and measurement techniques, the interest of researchers is moving toward 3D structures and 3D magnetization textures. Special attention is paid to the topological magnetization textures, particularly hopfions. In this paper, we investigate the magnetization dynamics of the hopfion through the numerical solution of the eigenvalue problem. We show that the spectrum of spin-wave modes of the hopfion is much richer than those attainable in ferromagnetic resonance experiments or time-domain simulations reported so far. We identified four groups of modes that differ in the character of oscillations (clockwise or counter-clockwise rotation sense), the position of an average amplitude localization along the radial direction, and different oscillations in the vertical cross section. The knowledge of the full spin-wave spectrum shall help in hopfion identification, understanding of the interaction between spin waves and hopfion dynamics as well as the development of the potential of hopfion in spintronic and magnonic applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close With the development of new nanofabrication technologies and measurement techniques, the interest of researchers is moving toward 3D structures and 3D magnetization textures. Special attention is paid to the topological magnetization textures, particularly hopfions. In this paper, we investigate the magnetization dynamics of the hopfion through the numerical solution of the eigenvalue problem. We show that the spectrum of spin-wave modes of the hopfion is much richer than those attainable in ferromagnetic resonance experiments or time-domain simulations reported so far. We identified four groups of modes that differ in the character of oscillations (clockwise or counter-clockwise rotation sense), the position of an average amplitude localization along the radial direction, and different oscillations in the vertical cross section. The knowledge of the full spin-wave spectrum shall help in hopfion identification, understanding of the interaction between spin waves and hopfion dynamics as well as the development of the potential of hopfion in spintronic and magnonic applications. Close https://doi.org/10.1063/5.0100484 doi:10.1063/5.0100484 Close
109.	Krzysztof Szulc, Silvia Tacchi, Aurelio Hierro-Rodríguez, Javier Díaz, Paweł Gruszecki, Piotr Graczyk, Carlos Quirós, Daniel Markó, José Ignacio Martín, María Vélez, David S Schmool, Giovanni Carlotti, Maciej Krawczyk, Luis Manuel Álvarez-Prado Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers ACS Nano, 0 (0), pp. 0, 2022, (PMID: 36043881). Abstract \| Links \| BibTeX @article{doi:10.1021/acsnano.2c04256, title = {Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers}, author = {Krzysztof Szulc and Silvia Tacchi and Aurelio Hierro-Rodríguez and Javier Díaz and Paweł Gruszecki and Piotr Graczyk and Carlos Quirós and Daniel Markó and José Ignacio Martín and María Vélez and David S Schmool and Giovanni Carlotti and Maciej Krawczyk and Luis Manuel Álvarez-Prado}, url = {https://doi.org/10.1021/acsnano.2c04256}, doi = {10.1021/acsnano.2c04256}, year = {2022}, date = {2022-08-31}, journal = {ACS Nano}, volume = {0}, number = {0}, pages = {0}, abstract = {Reconfigurable magnetization textures offer control of spin waves with promising properties for future low-power beyond-CMOS systems. However, materials with perpendicular magnetic anisotropy (PMA) suitable for stable magnetization-texture formation are characterized by high damping, which limits their applicability in magnonic devices. Here, we propose to overcome this limitation by using hybrid structures, i.e., a PMA layer magnetostatically coupled to a low-damping soft ferromagnetic film. We experimentally show that a periodic stripe-domain texture from a PMA layer is imprinted upon the soft layer and induces a nonreciprocal dispersion relation of the spin waves confined to the low-damping film. Moreover, an asymmetric bandgap features the spin-wave band diagram, which is a clear demonstration of collective spin-wave dynamics, a property characteristic for magnonic crystals with broken time-reversal symmetry. The composite character of the hybrid structure allows for stabilization of two magnetic states at remanence, with parallel and antiparallel orientation of net magnetization in hard and soft layers. The states can be switched using a low external magnetic field; therefore, the proposed system obtains an additional functionality of state reconfigurability. This study offers a link between reconfigurable magnetization textures and low-damping spin-wave dynamics, providing an opportunity to create miniaturized, programmable, and energy-efficient signal processing devices operating at high frequencies.}, note = {PMID: 36043881}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Reconfigurable magnetization textures offer control of spin waves with promising properties for future low-power beyond-CMOS systems. However, materials with perpendicular magnetic anisotropy (PMA) suitable for stable magnetization-texture formation are characterized by high damping, which limits their applicability in magnonic devices. Here, we propose to overcome this limitation by using hybrid structures, i.e., a PMA layer magnetostatically coupled to a low-damping soft ferromagnetic film. We experimentally show that a periodic stripe-domain texture from a PMA layer is imprinted upon the soft layer and induces a nonreciprocal dispersion relation of the spin waves confined to the low-damping film. Moreover, an asymmetric bandgap features the spin-wave band diagram, which is a clear demonstration of collective spin-wave dynamics, a property characteristic for magnonic crystals with broken time-reversal symmetry. The composite character of the hybrid structure allows for stabilization of two magnetic states at remanence, with parallel and antiparallel orientation of net magnetization in hard and soft layers. The states can be switched using a low external magnetic field; therefore, the proposed system obtains an additional functionality of state reconfigurability. This study offers a link between reconfigurable magnetization textures and low-damping spin-wave dynamics, providing an opportunity to create miniaturized, programmable, and energy-efficient signal processing devices operating at high frequencies. Close https://doi.org/10.1021/acsnano.2c04256 doi:10.1021/acsnano.2c04256 Close
108.	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
107.	Szymon Mieszczak, Maciej Krawczyk, Jarosław W. Kłos Spin-wave localization on phasonic defects in a one-dimensional magnonic quasicrystal Phys. Rev. B, 106 , pp. 064430, 2022. Abstract \| Links \| BibTeX @article{PhysRevB.106.064430, title = {Spin-wave localization on phasonic defects in a one-dimensional magnonic quasicrystal}, author = {Szymon Mieszczak and Maciej Krawczyk and Jarosław W. Kłos}, url = {https://link.aps.org/doi/10.1103/PhysRevB.106.064430}, doi = {10.1103/PhysRevB.106.064430}, year = {2022}, date = {2022-08-25}, journal = {Phys. Rev. B}, volume = {106}, pages = {064430}, publisher = {American Physical Society}, abstract = {We report on the evolution of the spin-wave spectrum under structural disorder introduced intentionally into a one-dimensional magnonic quasicrystal. We study theoretically a system composed of ferromagnetic strips arranged in a Fibonacci sequence. We considered several stages of disorder in the form of phasonic defects, where different rearrangements of strips are introduced. By transition from the quasiperiodic order towards disorder, we show a gradual degradation of spin-wave fractal spectra and closing of the frequency gaps. In particular, the phasonic defects lead to the disappearance of the van Hove singularities at the frequency gap edges by moving modes into the frequency gaps and creating new modes inside the frequency gaps. These modes disperse and eventually can close the gap, with increasing disorder levels. The work reveals how the presence of disorder modifies the intrinsic spin-wave localization existing in undefected magnonic quasicrystals. The paper contributes to the knowledge of magnonic Fibonacci quasicrystals and opens the way to study of the phasonic defects in two-dimensional magnonic quasicrystals.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We report on the evolution of the spin-wave spectrum under structural disorder introduced intentionally into a one-dimensional magnonic quasicrystal. We study theoretically a system composed of ferromagnetic strips arranged in a Fibonacci sequence. We considered several stages of disorder in the form of phasonic defects, where different rearrangements of strips are introduced. By transition from the quasiperiodic order towards disorder, we show a gradual degradation of spin-wave fractal spectra and closing of the frequency gaps. In particular, the phasonic defects lead to the disappearance of the van Hove singularities at the frequency gap edges by moving modes into the frequency gaps and creating new modes inside the frequency gaps. These modes disperse and eventually can close the gap, with increasing disorder levels. The work reveals how the presence of disorder modifies the intrinsic spin-wave localization existing in undefected magnonic quasicrystals. The paper contributes to the knowledge of magnonic Fibonacci quasicrystals and opens the way to study of the phasonic defects in two-dimensional magnonic quasicrystals. Close https://link.aps.org/doi/10.1103/PhysRevB.106.064430 doi:10.1103/PhysRevB.106.064430 Close
106.	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
105.	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
104.	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
103.	Mateusz Gołȩbiewski, Paweł Gruszecki, Maciej Krawczyk Self-Imaging of Spin Waves in Thin, Multimode Ferromagnetic Waveguides IEEE Transactions on Magnetics, 58 (8), pp. 1-5, 2022, ISSN: 1941-0069. Abstract \| Links \| BibTeX @article{9668947, title = {Self-Imaging of Spin Waves in Thin, Multimode Ferromagnetic Waveguides}, author = {Mateusz Gołȩbiewski and Paweł Gruszecki and Maciej Krawczyk}, doi = {10.1109/TMAG.2022.3140280}, issn = {1941-0069}, year = {2022}, date = {2022-08-01}, journal = {IEEE Transactions on Magnetics}, volume = {58}, number = {8}, pages = {1-5}, abstract = {Self-imaging of waves is an intriguing and spectacular effect. The phenomenon was first observed for light in 1836 by Henry Fox Talbot and to this day is the subject of research in many areas of physics, for various types of waves and in terms of different applications. This article is a Talbot-effect study for spin waves (SWs) in systems composed of a thin, ferromagnetic waveguide with a series of single-mode sources of SWs flowing into it. The proposed systems are studied with the use of micromagnetic simulations, and the SW self-imaging dependencies on many parameters are examined. We formulated conditions required for the formation of self-images and suitable for experimental realization. The results of the research form the basis for the further development of self-imaging-based magnonic devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Self-imaging of waves is an intriguing and spectacular effect. The phenomenon was first observed for light in 1836 by Henry Fox Talbot and to this day is the subject of research in many areas of physics, for various types of waves and in terms of different applications. This article is a Talbot-effect study for spin waves (SWs) in systems composed of a thin, ferromagnetic waveguide with a series of single-mode sources of SWs flowing into it. The proposed systems are studied with the use of micromagnetic simulations, and the SW self-imaging dependencies on many parameters are examined. We formulated conditions required for the formation of self-images and suitable for experimental realization. The results of the research form the basis for the further development of self-imaging-based magnonic devices. Close doi:10.1109/TMAG.2022.3140280 Close
102.	Przemysław Chełminiak Non-linear diffusion with stochastic resetting Journal of Physics A: Mathematical and Theoretical, 55 (38), pp. 384004, 2022. Abstract \| Links \| BibTeX @article{Che_miniak_2022, title = {Non-linear diffusion with stochastic resetting}, author = {Przemysław Chełminiak}, url = {https://doi.org/10.1088/1751-8121/ac870a}, doi = {10.1088/1751-8121/ac870a}, year = {2022}, date = {2022-08-01}, journal = {Journal of Physics A: Mathematical and Theoretical}, volume = {55}, number = {38}, pages = {384004}, publisher = {IOP Publishing}, abstract = {Resetting or restart, when applied to a stochastic process, usually brings its dynamics to a time-independent stationary state. In turn, the optimal resetting rate makes the mean time to reach a target to be finite and the shortest one. These and other innovative problems have been intensively studied over the last decade mainly in the case of ordinary diffusive processes. Intrigued by this fact we consider here the influence of stochastic resetting on the non-linear diffusion analysing its fundamental properties. We derive the exact formula for the mean squared displacement and demonstrate how it attains the steady-state value under the influence of the exponential resetting. This mechanism brings also about that the spatial support of the probability density function, which for the free non-linear diffusion is confined to the domain of a finite size, tends to span the entire set of real numbers. In addition, the first-passage properties for the non-linear diffusion intermittent by the exponential resetting are investigated. We find analytical expressions for the mean first-passage time and determine by means of the numerical method the optimal resetting rate which minimizes the mean time needed for a particle to reach a pre-determined target. Finally, we test and confirm the universal property that the relative fluctuation in the mean first-passage time of optimally restarted non-linear diffusion is equal to unity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Resetting or restart, when applied to a stochastic process, usually brings its dynamics to a time-independent stationary state. In turn, the optimal resetting rate makes the mean time to reach a target to be finite and the shortest one. These and other innovative problems have been intensively studied over the last decade mainly in the case of ordinary diffusive processes. Intrigued by this fact we consider here the influence of stochastic resetting on the non-linear diffusion analysing its fundamental properties. We derive the exact formula for the mean squared displacement and demonstrate how it attains the steady-state value under the influence of the exponential resetting. This mechanism brings also about that the spatial support of the probability density function, which for the free non-linear diffusion is confined to the domain of a finite size, tends to span the entire set of real numbers. In addition, the first-passage properties for the non-linear diffusion intermittent by the exponential resetting are investigated. We find analytical expressions for the mean first-passage time and determine by means of the numerical method the optimal resetting rate which minimizes the mean time needed for a particle to reach a pre-determined target. Finally, we test and confirm the universal property that the relative fluctuation in the mean first-passage time of optimally restarted non-linear diffusion is equal to unity. Close https://doi.org/10.1088/1751-8121/ac870a doi:10.1088/1751-8121/ac870a Close
101.	L. Chotorlishvili, Xi-guang Wang, Anna Dyrdał, Guang-hua Guo, Vitalii K. Dugaev, Józef Barnaś, J. Berakdar Rectification of the spin Seebeck current in noncollinear antiferromagnets Phys. Rev. B, 106 (1), pp. 014417, 2022, ISSN: 2469-9969. Abstract \| Links \| BibTeX @article{Chotorlishvili2022, title = {Rectification of the spin Seebeck current in noncollinear antiferromagnets}, author = {L. Chotorlishvili and Xi-guang Wang and Anna Dyrdał and Guang-hua Guo and Vitalii K. Dugaev and Józef Barnaś and J. Berakdar}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.014417}, doi = {10.1103/PhysRevB.106.014417}, issn = {2469-9969}, year = {2022}, date = {2022-07-25}, journal = {Phys. Rev. B}, volume = {106}, number = {1}, pages = {014417}, abstract = {In the absence of an external magnetic field and a spin-polarized charge current, an antiferromagnetic system supports two degenerate magnon modes. An applied thermal bias activates the magnetic dynamics, leading to a magnon flow from the hot to the cold edge (magnonic spin Seebeck current). Both degenerate bands contribute to the magnon current but the orientations of the magnetic moments underlying the magnons are opposite in different bands. Therefore, while the magnon current is nonzero, the net spin current is zero. To obtain a nonzero net spin current, one needs to apply either a magnetic field or a spin-polarized charge current that lifts the bands' degeneracy. Here, attaching a thermal contact to one edge of a helical nanowire, we study three different magnonic spin currents: (i) the exchange, and (ii) Dzyaloshinskii–Moriya spin currents flowing along the helical nanowire, and (iii) magnonic spin current pumped into the adjacent normal-metal layer. We find that the combination of Dzyaloshinskii–Moriya interaction and external magnetic field substantially enhances the spin current compared to the current generated solely through a magnetic field. Due to nonreciprocal magnons and magnon dichroism effect, the Dzyaloshinskii–Moriya and exchange spin currents show left-right propagation asymmetry, with 20% of current rectification. The spin pumping current shows a slight asymmetry only in the case of a strong Dzyaloshinskii–Moriya interaction. The observed effects are explained in terms of the magnon dispersion relations and the magnon Doppler effect.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close In the absence of an external magnetic field and a spin-polarized charge current, an antiferromagnetic system supports two degenerate magnon modes. An applied thermal bias activates the magnetic dynamics, leading to a magnon flow from the hot to the cold edge (magnonic spin Seebeck current). Both degenerate bands contribute to the magnon current but the orientations of the magnetic moments underlying the magnons are opposite in different bands. Therefore, while the magnon current is nonzero, the net spin current is zero. To obtain a nonzero net spin current, one needs to apply either a magnetic field or a spin-polarized charge current that lifts the bands' degeneracy. Here, attaching a thermal contact to one edge of a helical nanowire, we study three different magnonic spin currents: (i) the exchange, and (ii) Dzyaloshinskii–Moriya spin currents flowing along the helical nanowire, and (iii) magnonic spin current pumped into the adjacent normal-metal layer. We find that the combination of Dzyaloshinskii–Moriya interaction and external magnetic field substantially enhances the spin current compared to the current generated solely through a magnetic field. Due to nonreciprocal magnons and magnon dichroism effect, the Dzyaloshinskii–Moriya and exchange spin currents show left-right propagation asymmetry, with 20% of current rectification. The spin pumping current shows a slight asymmetry only in the case of a strong Dzyaloshinskii–Moriya interaction. The observed effects are explained in terms of the magnon dispersion relations and the magnon Doppler effect. Close https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.014417 doi:10.1103/PhysRevB.106.014417 Close
100.	Mateusz Gołębiewski, Paweł Gruszecki, Maciej Krawczyk Self-Imaging Based Programmable Spin-Wave Lookup Tables Advanced Electronic Materials, n/a (n/a), pp. 2200373, 2022. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/aelm.202200373, title = {Self-Imaging Based Programmable Spin-Wave Lookup Tables}, author = {Mateusz Gołębiewski and Paweł Gruszecki and Maciej Krawczyk}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aelm.202200373}, doi = {https://doi.org/10.1002/aelm.202200373}, year = {2022}, date = {2022-07-21}, journal = {Advanced Electronic Materials}, volume = {n/a}, number = {n/a}, pages = {2200373}, abstract = {Abstract Inclusion of spin waves into the computing paradigm, where complementary metal-oxide-semiconductor devices are still at the fore, is now a challenge for scientists around the world. In this work, a wave phenomenon that has not yet been used in magnonics-self-imaging, also known as the Talbot effect, to design and simulate the operation of interference systems that perform logic functions on spin waves in thin ferromagnetic multimode waveguides is utilized. Lookup tables operating in this way are characterized by high programmability and scalability; thanks to which they are promising for their implementation in field-programmable gate arrays circuits, where multiple logic realizations can be obtained.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Abstract Inclusion of spin waves into the computing paradigm, where complementary metal-oxide-semiconductor devices are still at the fore, is now a challenge for scientists around the world. In this work, a wave phenomenon that has not yet been used in magnonics-self-imaging, also known as the Talbot effect, to design and simulate the operation of interference systems that perform logic functions on spin waves in thin ferromagnetic multimode waveguides is utilized. Lookup tables operating in this way are characterized by high programmability and scalability; thanks to which they are promising for their implementation in field-programmable gate arrays circuits, where multiple logic realizations can be obtained. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/aelm.202200373 doi:https://doi.org/10.1002/aelm.202200373 Close
99.	Mir Ali Jafari, A. A. Kordbacheh, Anna Dyrdał Electronic and magnetic properties of silicene monolayer under bi-axial mechanical strain: First principles study J. Magn. Magn. Mater., 554 , pp. 169260, 2022, ISSN: 0304-8853. Abstract \| Links \| BibTeX @article{Jafari2022b, title = {Electronic and magnetic properties of silicene monolayer under bi-axial mechanical strain: First principles study}, author = {Mir Ali Jafari and A. A. Kordbacheh and Anna Dyrdał}, url = {https://www.sciencedirect.com/science/article/pii/S0304885322002116?via%3Dihub}, doi = {10.1016/j.jmmm.2022.169260}, issn = {0304-8853}, year = {2022}, date = {2022-07-15}, journal = {J. Magn. Magn. Mater.}, volume = {554}, pages = {169260}, abstract = {Mechanical control of electronic and magnetic properties of 2D Van-der-Waals heterostructures gives new possibilities for further development of spintronics and information-related technologies. Using the density functional theory, we investigate the structural, electronic and magnetic properties of silicene monolayer with substituted Chromium atoms and under a small biaxial strain (-6% < e < 8%). Our results indicate that the Cr-doped silicene nanosheets without strain have magnetic metallic, half-metallic or semiconducting properties depending on the type of substitution. We also show that the magnetic moments associated with the monomer and vertical dimer substitutions change very weakly with strain. However, the magnetic moment associated with the horizontal dimer substitution decreases when either compressive or tensile strain is applied to the system. Additionally, we show that the largest semiconductor band-gap is approximately 0.13 eV under zero strain for the vertical Cr-doped silicene. Finally, biaxial compressive strain leads to irregular changes in the magnetic moment for Cr vertical dimer substitution.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Mechanical control of electronic and magnetic properties of 2D Van-der-Waals heterostructures gives new possibilities for further development of spintronics and information-related technologies. Using the density functional theory, we investigate the structural, electronic and magnetic properties of silicene monolayer with substituted Chromium atoms and under a small biaxial strain (-6% < e < 8%). Our results indicate that the Cr-doped silicene nanosheets without strain have magnetic metallic, half-metallic or semiconducting properties depending on the type of substitution. We also show that the magnetic moments associated with the monomer and vertical dimer substitutions change very weakly with strain. However, the magnetic moment associated with the horizontal dimer substitution decreases when either compressive or tensile strain is applied to the system. Additionally, we show that the largest semiconductor band-gap is approximately 0.13 eV under zero strain for the vertical Cr-doped silicene. Finally, biaxial compressive strain leads to irregular changes in the magnetic moment for Cr vertical dimer substitution. Close https://www.sciencedirect.com/science/article/pii/S0304885322002116?via%3Dihub doi:10.1016/j.jmmm.2022.169260 Close
98.	Szymon Mieszczak, Jarosław W. Kłos Interface modes in planar one-dimensional magnonic crystals Scientific Reports, 12 (1), pp. 11335, 2022, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{mieszczak_interface_2022, title = {Interface modes in planar one-dimensional magnonic crystals}, author = {Szymon Mieszczak and Jarosław W. Kłos}, url = {https://www.nature.com/articles/s41598-022-15328-x}, doi = {10.1038/s41598-022-15328-x}, issn = {2045-2322}, year = {2022}, date = {2022-07-05}, urldate = {2022-07-11}, journal = {Scientific Reports}, volume = {12}, number = {1}, pages = {11335}, abstract = {We present the concept of Zak phase for spin waves in planar magnonic crystals and discuss the existence condition of interface modes localized on the boundary between two magnonic crystals with centrosymmetric unit cells. Using the symmetry criterion and analyzing the logarithmic derivative of the Bloch function, we study the interface modes and demonstrate the bulk-to-edge correspondence. Our theoretical results are verified numerically and extended to the case in which one of the magnonic crystals has a non-centrosymmetric unit cells. We show that by shifting the unit cell, the interface modes can traverse between the band gap edges. Our work also investigate the role of the dipolar interaction, by comparison the systems both with exchange interaction only and combined dipolar-exchange interactions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We present the concept of Zak phase for spin waves in planar magnonic crystals and discuss the existence condition of interface modes localized on the boundary between two magnonic crystals with centrosymmetric unit cells. Using the symmetry criterion and analyzing the logarithmic derivative of the Bloch function, we study the interface modes and demonstrate the bulk-to-edge correspondence. Our theoretical results are verified numerically and extended to the case in which one of the magnonic crystals has a non-centrosymmetric unit cells. We show that by shifting the unit cell, the interface modes can traverse between the band gap edges. Our work also investigate the role of the dipolar interaction, by comparison the systems both with exchange interaction only and combined dipolar-exchange interactions. Close https://www.nature.com/articles/s41598-022-15328-x doi:10.1038/s41598-022-15328-x Close
97.	Surya Narayan Panda, Bivas Rana, YoshiChika Otani, Anjan Barman Role of Spin–Orbit Coupling on Ultrafast Spin Dynamics in Nonmagnet/Ferromagnet Heterostructures Advanced Quantum Technologies, 2022 , pp. 2200016, 2022. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/qute.202200016, title = {Role of Spin–Orbit Coupling on Ultrafast Spin Dynamics in Nonmagnet/Ferromagnet Heterostructures}, author = {Surya Narayan Panda and Bivas Rana and YoshiChika Otani and Anjan Barman}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202200016}, doi = {https://doi.org/10.1002/qute.202200016}, year = {2022}, date = {2022-07-01}, journal = {Advanced Quantum Technologies}, volume = {2022}, pages = {2200016}, abstract = {Abstract Spin–orbit coupling (SOC), the interaction between spin and orbital angular momentum of electrons, is imperative to control magnetic properties of nonmagnet (NM)/ferromagnet (FM) heterostructures and design energy-efficient and faster spin-based devices. Here, femtosecond pulsed laser-induced time-resolved magneto-optical Kerr effect magnetometry is employed to investigate magnetization dynamics in different NM/Co20Fe60B20 heterostructures, where the NM layer varies as Cu, Ta, W, Pt, Ta/Ru/Ta, and Si/SiO2 (no underlayer) that differ in SOC strength. It is observed that there is a systematic variation in ultrafast demagnetization time (τm), fast remagnetization time (τr), and Gilbert damping parameter (α) with the SOC strength of the underlayer and an inverse relationship between α and τm, τr is established due to the dominant contribution of spin current transport in ultrafast demagnetization and fast remagnetization processes. The spin pumping formalism estimates the effective spin-mixing conductance (Geff) for different interfaces, which signifies that the high SOC strength of underlayers results in high Geff indicating more efficient transport of spin current through it. This study suggests that the SOC strength of the NM underlayer plays a significant role in controlling the ultrafast demagnetization process through interfacial spin current transport in a NM/FM heterostructure which can be beneficial for the development of ultrafast spintronics devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Abstract Spin–orbit coupling (SOC), the interaction between spin and orbital angular momentum of electrons, is imperative to control magnetic properties of nonmagnet (NM)/ferromagnet (FM) heterostructures and design energy-efficient and faster spin-based devices. Here, femtosecond pulsed laser-induced time-resolved magneto-optical Kerr effect magnetometry is employed to investigate magnetization dynamics in different NM/Co20Fe60B20 heterostructures, where the NM layer varies as Cu, Ta, W, Pt, Ta/Ru/Ta, and Si/SiO2 (no underlayer) that differ in SOC strength. It is observed that there is a systematic variation in ultrafast demagnetization time (τm), fast remagnetization time (τr), and Gilbert damping parameter (α) with the SOC strength of the underlayer and an inverse relationship between α and τm, τr is established due to the dominant contribution of spin current transport in ultrafast demagnetization and fast remagnetization processes. The spin pumping formalism estimates the effective spin-mixing conductance (Geff) for different interfaces, which signifies that the high SOC strength of underlayers results in high Geff indicating more efficient transport of spin current through it. This study suggests that the SOC strength of the NM underlayer plays a significant role in controlling the ultrafast demagnetization process through interfacial spin current transport in a NM/FM heterostructure which can be beneficial for the development of ultrafast spintronics devices. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202200016 doi:https://doi.org/10.1002/qute.202200016 Close
96.	M. Kaczor, I. Tralle, P. Jakubczyk, Stefan Stagraczyński, L. Chotorlishvili Switching of the information backflow between a helical spin system and non-Markovian bath Annals of Physics, 442 , pp. 168918, 2022, ISSN: 0003-4916. Abstract \| Links \| BibTeX @article{Kaczor2022, title = {Switching of the information backflow between a helical spin system and non-Markovian bath}, author = {M. Kaczor and I. Tralle and P. Jakubczyk and Stefan Stagraczyński and L. Chotorlishvili}, url = {https://www.sciencedirect.com/science/article/pii/S0003491622000999?via%3Dihub}, doi = {10.1016/j.aop.2022.168918}, issn = {0003-4916}, year = {2022}, date = {2022-07-01}, journal = {Annals of Physics}, volume = {442}, pages = {168918}, abstract = {The dissipative dynamics of the spin chain coupled to the non-Markovian magnonic reservoir was studied. The chirality of the chain is formed due to the magnetoelectric coupling. We explored the sign of the trace distance derivative and found the alternating positive/negative periods in system’s time evolution. The negative sign is associated with the flow of information from the system to the bath and decrease in states distinguishability, while the positive sign is related to the flow of the information in the opposite direction and increase in distinguishability. We found the distinct effect of the applied electric and magnetic fields. While the Dzyaloshinskii–Moriya interaction and external electric field lead to reshuffling of the periods, the applied magnetic field leads to the swift positive–negative transitions. Thus, in the helical quantum rings coupled to the non-Markovian magnonic baths, it is possible to control the directions of information flow through the external fields.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The dissipative dynamics of the spin chain coupled to the non-Markovian magnonic reservoir was studied. The chirality of the chain is formed due to the magnetoelectric coupling. We explored the sign of the trace distance derivative and found the alternating positive/negative periods in system’s time evolution. The negative sign is associated with the flow of information from the system to the bath and decrease in states distinguishability, while the positive sign is related to the flow of the information in the opposite direction and increase in distinguishability. We found the distinct effect of the applied electric and magnetic fields. While the Dzyaloshinskii–Moriya interaction and external electric field lead to reshuffling of the periods, the applied magnetic field leads to the swift positive–negative transitions. Thus, in the helical quantum rings coupled to the non-Markovian magnonic baths, it is possible to control the directions of information flow through the external fields. Close https://www.sciencedirect.com/science/article/pii/S0003491622000999?via%3Dihub doi:10.1016/j.aop.2022.168918 Close
95.	M Szafrański, Zbigniew Tylczyński, M Wiesner, P Czarnecki, V V Ghazaryan, A M Petrosyan Above-room-temperature ferroelectricity and piezoelectric activity of dimethylglycinium-dimethylglycine chloride Materials & Design, 220 , pp. 110893, 2022, ISSN: 0264-1275. Abstract \| Links \| BibTeX @article{SZAFRANSKI2022110893, title = {Above-room-temperature ferroelectricity and piezoelectric activity of dimethylglycinium-dimethylglycine chloride}, author = {M Szafrański and Zbigniew Tylczyński and M Wiesner and P Czarnecki and V V Ghazaryan and A M Petrosyan}, url = {https://www.sciencedirect.com/science/article/pii/S0264127522005159}, doi = {https://doi.org/10.1016/j.matdes.2022.110893}, issn = {0264-1275}, year = {2022}, date = {2022-06-27}, journal = {Materials & Design}, volume = {220}, pages = {110893}, abstract = {Heavy-metal-free ferroelectrics are sought as environmentally compatible alternatives to commonly used inorganic oxides. Here, we demonstrate direct evidence of the ferroelectric properties of a hybrid organic–inorganic material, dimethylglycinium-dimethylglycine chloride. At room temperature, the compound crystallizes in the polar space group P21 and exhibits a switchable spontaneous polarization of 1.9 μC cm−2. Ferroelectric properties are preserved in a wide temperature range up to about 401 K, where the crystal undergoes the transition to the paraelectric phase of the space group P21/c. The temperature-dependent single-crystal X-ray diffraction study and the calorimetric data indicate an order–disorder contribution to the transition mechanism, which is consistent with the critical slowing down of the dielectric relaxation observed near the Curie point. The spontaneous polarization results from ionic displacements that are induced by changes in the disordering of the dimeric cations. In the ferroelectric phase, the crystal exhibits remarkable piezoelectric activity. The electromechanical and elastic properties of the material were thoroughly characterized.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Heavy-metal-free ferroelectrics are sought as environmentally compatible alternatives to commonly used inorganic oxides. Here, we demonstrate direct evidence of the ferroelectric properties of a hybrid organic–inorganic material, dimethylglycinium-dimethylglycine chloride. At room temperature, the compound crystallizes in the polar space group P21 and exhibits a switchable spontaneous polarization of 1.9 μC cm−2. Ferroelectric properties are preserved in a wide temperature range up to about 401 K, where the crystal undergoes the transition to the paraelectric phase of the space group P21/c. The temperature-dependent single-crystal X-ray diffraction study and the calorimetric data indicate an order–disorder contribution to the transition mechanism, which is consistent with the critical slowing down of the dielectric relaxation observed near the Curie point. The spontaneous polarization results from ionic displacements that are induced by changes in the disordering of the dimeric cations. In the ferroelectric phase, the crystal exhibits remarkable piezoelectric activity. The electromechanical and elastic properties of the material were thoroughly characterized. Close https://www.sciencedirect.com/science/article/pii/S0264127522005159 doi:https://doi.org/10.1016/j.matdes.2022.110893 Close
94.	Amir Nasser Zarezad, Anna Dyrdał Bilinear magnetoresistance in topological insulators: Role of magnetic disorder J. Magn. Magn. Mater., 552 , pp. 169167, 2022, ISSN: 0304-8853. Abstract \| Links \| BibTeX @article{Zarezad2022, title = {Bilinear magnetoresistance in topological insulators: Role of magnetic disorder}, author = {Amir Nasser Zarezad and Anna Dyrdał}, url = {https://www.sciencedirect.com/science/article/pii/S0304885322001329?via%3Dihub}, doi = {10.1016/j.jmmm.2022.169167}, issn = {0304-8853}, year = {2022}, date = {2022-06-15}, journal = {J. Magn. Magn. Mater.}, volume = {552}, pages = {169167}, abstract = {Bilinear magnetoresistance is a nonlinear transport phenomenon that scales linearly with the electric and magnetic fields, and appears in nonmagnetic systems with strong spin–orbit coupling, such as topological insulators (TIs). Using the semiclassical Boltzmann theory and generalized relaxation time approximation, we consider in detail the bilinear magnetoresistance in an effective model describing surface states of three-dimensional topological insulators. We show that the presence of magnetic impurities remarkably modifies the BMR signal. In general, scattering on magnetic impurities reduces magnitude of BMR. Apart from this, an additional modulation of the angular dependence of BMR appears when the spin-dependent component of the impurity potential dominates the scalar one.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Bilinear magnetoresistance is a nonlinear transport phenomenon that scales linearly with the electric and magnetic fields, and appears in nonmagnetic systems with strong spin–orbit coupling, such as topological insulators (TIs). Using the semiclassical Boltzmann theory and generalized relaxation time approximation, we consider in detail the bilinear magnetoresistance in an effective model describing surface states of three-dimensional topological insulators. We show that the presence of magnetic impurities remarkably modifies the BMR signal. In general, scattering on magnetic impurities reduces magnitude of BMR. Apart from this, an additional modulation of the angular dependence of BMR appears when the spin-dependent component of the impurity potential dominates the scalar one. Close https://www.sciencedirect.com/science/article/pii/S0304885322001329?via%3Dihub doi:10.1016/j.jmmm.2022.169167 Close
93.	Agnieszka Cichy, Konrad J. Kapcia, Andrzej Ptok Connection between the semiconductor-superconductor transition and the spin-polarized superconducting phase in the honeycomb lattice Phys. Rev. B, 105 , pp. 214510, 2022. Abstract \| Links \| BibTeX @article{Cichy2022, title = {Connection between the semiconductor-superconductor transition and the spin-polarized superconducting phase in the honeycomb lattice}, author = {Agnieszka Cichy and Konrad J. Kapcia and Andrzej Ptok}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.214510}, doi = {10.1103/PhysRevB.105.214510}, year = {2022}, date = {2022-06-14}, journal = {Phys. Rev. B}, volume = {105}, pages = {214510}, abstract = {The band structure of noninteracting fermions in the honeycomb lattice exhibits the Dirac cones at the corners of the Brillouin zone. As a consequence, fermions in this lattice manifest a semiconducting behavior below some critical value of the on-site attraction Uc. However, above Uc, the superconducting phase can occur. We discuss an interplay between the semiconductor-superconductor transition and the possibility of realization of the spin-polarized superconductivity (the so-called Sarma phase). We show that the critical interaction can be tuned by the next-nearest-neighbor (NNN) hopping in the absence of the magnetic field. Moreover, a critical value of the NNN hopping exists, defining a range of parameters for which the semiconducting phase can emerge. In the weak-coupling limit case, this quantum phase transition occurs for the absolute value of the NNN hopping equal to one third of the hopping between the nearest neighbors. Similarly, in the presence of the magnetic field, the Sarma phase can appear but only in a range of parameters for which initially the semiconducting state is observed. Both of these aspects are attributed to the Lifshitz transition, which is induced by the NNN hopping as well as the external magnetic field.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The band structure of noninteracting fermions in the honeycomb lattice exhibits the Dirac cones at the corners of the Brillouin zone. As a consequence, fermions in this lattice manifest a semiconducting behavior below some critical value of the on-site attraction Uc. However, above Uc, the superconducting phase can occur. We discuss an interplay between the semiconductor-superconductor transition and the possibility of realization of the spin-polarized superconductivity (the so-called Sarma phase). We show that the critical interaction can be tuned by the next-nearest-neighbor (NNN) hopping in the absence of the magnetic field. Moreover, a critical value of the NNN hopping exists, defining a range of parameters for which the semiconducting phase can emerge. In the weak-coupling limit case, this quantum phase transition occurs for the absolute value of the NNN hopping equal to one third of the hopping between the nearest neighbors. Similarly, in the presence of the magnetic field, the Sarma phase can appear but only in a range of parameters for which initially the semiconducting state is observed. Both of these aspects are attributed to the Lifshitz transition, which is induced by the NNN hopping as well as the external magnetic field. Close https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.214510 doi:10.1103/PhysRevB.105.214510 Close
92.	Tomasz Ślusarski, Kacper Wrześniewski, Ireneusz Weymann Numerical renormalization group study of the Loschmidt echo in Kondo systems Scientific Reports, 12 , pp. 9799, 2022. Abstract \| Links \| BibTeX @article{Ślusarski2022, title = {Numerical renormalization group study of the Loschmidt echo in Kondo systems}, author = {Tomasz Ślusarski and Kacper Wrześniewski and Ireneusz Weymann}, url = {https://www.nature.com/articles/s41598-022-14108-x}, doi = {10.1038/s41598-022-14108-x}, year = {2022}, date = {2022-06-13}, journal = {Scientific Reports}, volume = {12}, pages = {9799}, abstract = {We study the dynamical properties of the one-channel and two-channel spin-1/2 Kondo models after quenching in Hamiltonian variables. Eigen spectrum of the initial and final Hamiltonians is calculated by using the numerical renormalization group method implemented within the matrix product states formalism. We consider multiple quench protocols in the considered Kondo systems, also in the presence of external magnetic field of different intensities. The main emphasis is put on the analysis of the behavior of the Loschmidt echo L(t), which measures the ability of the system’s revival to its initial state after a quench. We show that the decay of the Loschmidt echo strongly depends on the type of quench and the ground state of the system. For the one-channel Kondo model, we show that L(t) decays as, L(t)∼(t⋅TK)^−1.4, where TK is the Kondo temperature, while for the two-channel Kondo model, we demonstrate that the decay is slower and given by L(t)∼(t⋅TK)^−0.7. In addition, we also determine the dynamical behavior of the impurity’s magnetization, which sheds light on identification of the relevant time scales in the system’s dynamics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We study the dynamical properties of the one-channel and two-channel spin-1/2 Kondo models after quenching in Hamiltonian variables. Eigen spectrum of the initial and final Hamiltonians is calculated by using the numerical renormalization group method implemented within the matrix product states formalism. We consider multiple quench protocols in the considered Kondo systems, also in the presence of external magnetic field of different intensities. The main emphasis is put on the analysis of the behavior of the Loschmidt echo L(t), which measures the ability of the system’s revival to its initial state after a quench. We show that the decay of the Loschmidt echo strongly depends on the type of quench and the ground state of the system. For the one-channel Kondo model, we show that L(t) decays as, L(t)∼(t⋅TK)^−1.4, where TK is the Kondo temperature, while for the two-channel Kondo model, we demonstrate that the decay is slower and given by L(t)∼(t⋅TK)^−0.7. In addition, we also determine the dynamical behavior of the impurity’s magnetization, which sheds light on identification of the relevant time scales in the system’s dynamics. Close https://www.nature.com/articles/s41598-022-14108-x doi:10.1038/s41598-022-14108-x Close
91.	Vrishali Sonar, Rohan Dehankar, K. P. Vijayalakshmi, Natalio Mingo, Ankita Katre Site-independent strong phonon-vacancy scattering in high-temperature ceramics ZrB2 and HfB2 Phys. Rev. Materials, 6 , pp. 065403, 2022. Abstract \| Links \| BibTeX @article{Sonar2022, title = {Site-independent strong phonon-vacancy scattering in high-temperature ceramics ZrB2 and HfB2}, author = {Vrishali Sonar and Rohan Dehankar and K. P. Vijayalakshmi and Natalio Mingo and Ankita Katre}, url = {https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.6.065403}, doi = {10.1103/PhysRevMaterials.6.065403}, year = {2022}, date = {2022-06-10}, journal = {Phys. Rev. Materials}, volume = {6}, pages = {065403}, abstract = {Similar effects of metal and boron vacancies on phonon scattering and lattice thermal conductivity (κl) of ZrB2 and HfB2 are reported. These defects challenge the conventional understanding that associates larger impacts to bigger defects. We find the underlying reason to be a strong local perturbation caused by boron vacancy that substantially changes the interatomic force constants. In contrast, a long ranged but weaker perturbation is seen in the case of metal vacancy. We show that these behaviors originate from a mixed metallic and covalent bonding nature in the metal diborides. The thermal transport calculations are performed in a complete ab initio framework based on Boltzmann transport equation and density functional theory. Phonon-vacancy scattering is calculated using ab initio Green's function approach. Effects of natural isotopes and grain boundaries on κl are also systematically investigated, however we find an influential role of vacancies to explain large variations seen in the experiments. We further report a two-order of magnitude difference between the amorphous and pure-crystal limits. Our results outline significant material design aspects for these multifunctional high-temperature ceramics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Similar effects of metal and boron vacancies on phonon scattering and lattice thermal conductivity (κl) of ZrB2 and HfB2 are reported. These defects challenge the conventional understanding that associates larger impacts to bigger defects. We find the underlying reason to be a strong local perturbation caused by boron vacancy that substantially changes the interatomic force constants. In contrast, a long ranged but weaker perturbation is seen in the case of metal vacancy. We show that these behaviors originate from a mixed metallic and covalent bonding nature in the metal diborides. The thermal transport calculations are performed in a complete ab initio framework based on Boltzmann transport equation and density functional theory. Phonon-vacancy scattering is calculated using ab initio Green's function approach. Effects of natural isotopes and grain boundaries on κl are also systematically investigated, however we find an influential role of vacancies to explain large variations seen in the experiments. We further report a two-order of magnitude difference between the amorphous and pure-crystal limits. Our results outline significant material design aspects for these multifunctional high-temperature ceramics. Close https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.6.065403 doi:10.1103/PhysRevMaterials.6.065403 Close
90.	Andriy E. Serebryannikov, Diana C Skigin, Guy A E Vandenbosch, Ekmel Ozbay Multifunctional blazed gratings for multiband spatial filtering, retroreflection, splitting, and demultiplexing based on C2 symmetric photonic crystals Journal of Applied Physics, 131 (22), pp. 223101, 2022. Links \| BibTeX @article{doi:10.1063/5.0093989, title = {Multifunctional blazed gratings for multiband spatial filtering, retroreflection, splitting, and demultiplexing based on C2 symmetric photonic crystals}, author = {Andriy E. Serebryannikov and Diana C Skigin and Guy A E Vandenbosch and Ekmel Ozbay}, url = {https://doi.org/10.1063/5.0093989}, doi = {10.1063/5.0093989}, year = {2022}, date = {2022-06-08}, journal = {Journal of Applied Physics}, volume = {131}, number = {22}, pages = {223101}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://doi.org/10.1063/5.0093989 doi:10.1063/5.0093989 Close
89.	Ichiro Inoue, Victor Tkachenko, Konrad J. Kapcia, Vladimir Lipp, Beata Ziaja, Yuichi Inubushi, Toru Hara, Makina Yabashi, Eiji Nishibori Delayed Onset and Directionality of X-Ray-Induced Atomic Displacements Observed on Subatomic Length Scales Phys. Rev. Lett., 128 , pp. 223203, 2022. Abstract \| Links \| BibTeX @article{Inoue2022, title = {Delayed Onset and Directionality of X-Ray-Induced Atomic Displacements Observed on Subatomic Length Scales}, author = {Ichiro Inoue and Victor Tkachenko and Konrad J. Kapcia and Vladimir Lipp and Beata Ziaja and Yuichi Inubushi and Toru Hara and Makina Yabashi and Eiji Nishibori}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.223203}, doi = {10.1103/PhysRevLett.128.223203}, year = {2022}, date = {2022-06-01}, journal = {Phys. Rev. Lett.}, volume = {128}, pages = {223203}, abstract = {Transient structural changes of Al2O3 on subatomic length scales following irradiation with an intense x-ray laser pulse (photon energy: 8.70 keV; pulse duration: 6 fs; fluence: 8×102 J/cm2) have been investigated by using an x-ray pump x-ray probe technique. The measurement reveals that aluminum and oxygen atoms remain in their original positions by ∼20 fs after the intensity maximum of the pump pulse, followed by directional atomic displacements at the fixed unit cell parameters. By comparing the experimental results and theoretical simulations, we interpret that electron excitation and relaxation triggered by the pump pulse modify the potential energy surface and drives the directional atomic displacements. Our results indicate that high-resolution x-ray structural analysis with the accuracy of 0.01 Å is feasible even with intense x-ray pulses by making the pulse duration shorter than the timescale needed to complete electron excitation and relaxation processes, which usually take up to a few tens of femtoseconds.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Transient structural changes of Al2O3 on subatomic length scales following irradiation with an intense x-ray laser pulse (photon energy: 8.70 keV; pulse duration: 6 fs; fluence: 8×102 J/cm2) have been investigated by using an x-ray pump x-ray probe technique. The measurement reveals that aluminum and oxygen atoms remain in their original positions by ∼20 fs after the intensity maximum of the pump pulse, followed by directional atomic displacements at the fixed unit cell parameters. By comparing the experimental results and theoretical simulations, we interpret that electron excitation and relaxation triggered by the pump pulse modify the potential energy surface and drives the directional atomic displacements. Our results indicate that high-resolution x-ray structural analysis with the accuracy of 0.01 Å is feasible even with intense x-ray pulses by making the pulse duration shorter than the timescale needed to complete electron excitation and relaxation processes, which usually take up to a few tens of femtoseconds. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.223203 doi:10.1103/PhysRevLett.128.223203 Close
88.	Aleksandra Trzaskowska, Sławomir Mielcarek, Tomasz Lehmann, Ewa Pruszyńska-Oszmałek, Paweł Kołodziejski, Maciej Głowacki Mechanical properties of the mouse femur after treatment with diclofenac and running exercises Acta of Bioengineering and Biomechanics, 24 (2), pp. null, 2022. Abstract \| Links \| BibTeX @article{TrzaskowskaMechanical2022, title = {Mechanical properties of the mouse femur after treatment with diclofenac and running exercises}, author = {Aleksandra Trzaskowska and Sławomir Mielcarek and Tomasz Lehmann and Ewa Pruszyńska-Oszmałek and Paweł Kołodziejski and Maciej Głowacki}, url = {https://www.actabio.pwr.wroc.pl/Vol24No2/33.pdf}, doi = {10.37190/abb-02061-2022-03}, year = {2022}, date = {2022-05-26}, journal = {Acta of Bioengineering and Biomechanics}, volume = {24}, number = {2}, pages = {null}, abstract = {The flexible properties of the bone are essential for the movement and protection of vital organs. The ability of a bone to resist fractures under the influence of large muscles and physical activity depends on its established mechanical properties. This article discusses how exercise such as treadmill running and taking non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, affect the musculoskeletal system by modifying the elastic and thermal properties of the left femur of a mouse. Methods: The research was conducted using 9-week-old C57BL/6J female mice. In order to investigate the elastic and thermal properties of bones, dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were performed. Results: The study of elastic properties, followed by in-depth statistical analysis, shows that taking diclofenac slightly reduces the elastic parameters of the bones under study. These changes are more pronounced in DSC studies, the shift of the observed endothermic peaks is on the order of several degrees with a simultaneous increase in the enthalpy of this process. Conclusions: The opposite effect of the applied factors – diclofenac and running – on the elastic properties of the bones of the examined mice was found. The external factors – running and diclofenac – modify the basic parameters of the endothermic process associated with the release of water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The flexible properties of the bone are essential for the movement and protection of vital organs. The ability of a bone to resist fractures under the influence of large muscles and physical activity depends on its established mechanical properties. This article discusses how exercise such as treadmill running and taking non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, affect the musculoskeletal system by modifying the elastic and thermal properties of the left femur of a mouse. Methods: The research was conducted using 9-week-old C57BL/6J female mice. In order to investigate the elastic and thermal properties of bones, dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were performed. Results: The study of elastic properties, followed by in-depth statistical analysis, shows that taking diclofenac slightly reduces the elastic parameters of the bones under study. These changes are more pronounced in DSC studies, the shift of the observed endothermic peaks is on the order of several degrees with a simultaneous increase in the enthalpy of this process. Conclusions: The opposite effect of the applied factors – diclofenac and running – on the elastic properties of the bones of the examined mice was found. The external factors – running and diclofenac – modify the basic parameters of the endothermic process associated with the release of water. Close https://www.actabio.pwr.wroc.pl/Vol24No2/33.pdf doi:10.37190/abb-02061-2022-03 Close
87.	Angshuman Deka, Bivas Rana, Ryo Anami, Katsuya Miura, Hiromasa Takahashi, YoshiChika Otani, Yasuhiro Fukuma Electric field induced parametric excitation of exchange magnons in a CoFeB/MgO junction Phys. Rev. Research, 4 , pp. 023139, 2022. Abstract \| Links \| BibTeX @article{PhysRevResearch.4.023139, title = {Electric field induced parametric excitation of exchange magnons in a CoFeB/MgO junction}, author = {Angshuman Deka and Bivas Rana and Ryo Anami and Katsuya Miura and Hiromasa Takahashi and YoshiChika Otani and Yasuhiro Fukuma}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.4.023139}, doi = {10.1103/PhysRevResearch.4.023139}, year = {2022}, date = {2022-05-20}, journal = {Phys. Rev. Research}, volume = {4}, pages = {023139}, publisher = {American Physical Society}, abstract = {Inspired by the success of field-effect transistors in electronics, electric field controlled magnetization dynamics has emerged as an important integrant in low-power spintronic devices. Here, we demonstrate electric field induced parametric excitation for CoFeB/MgO junctions by using interfacial in-plane magnetic anisotropy (IMA). When the IMA and the external magnetic field are parallel to each other, magnons are efficiently excited by electric field induced parametric resonance. The corresponding wavelengths are estimated to be tuned down to exchange interaction length scales by changing the input power and frequency of the applied voltage. A generalized phenomenological model is developed to explain the underlying role of the electric field torque. Electric field control of IMA is shown to be the origin for excitation of both uniform and parametric resonance modes in the in-plane magnetized sample, a crucial element for purely electric field induced magnetization dynamics. Electric field excitation of exchange magnons, with no Joule heating, offers a good opportunity for developing nanoscale magnonic devices and exploring various nonlinear dynamics in nanomagnetic systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Inspired by the success of field-effect transistors in electronics, electric field controlled magnetization dynamics has emerged as an important integrant in low-power spintronic devices. Here, we demonstrate electric field induced parametric excitation for CoFeB/MgO junctions by using interfacial in-plane magnetic anisotropy (IMA). When the IMA and the external magnetic field are parallel to each other, magnons are efficiently excited by electric field induced parametric resonance. The corresponding wavelengths are estimated to be tuned down to exchange interaction length scales by changing the input power and frequency of the applied voltage. A generalized phenomenological model is developed to explain the underlying role of the electric field torque. Electric field control of IMA is shown to be the origin for excitation of both uniform and parametric resonance modes in the in-plane magnetized sample, a crucial element for purely electric field induced magnetization dynamics. Electric field excitation of exchange magnons, with no Joule heating, offers a good opportunity for developing nanoscale magnonic devices and exploring various nonlinear dynamics in nanomagnetic systems. Close https://link.aps.org/doi/10.1103/PhysRevResearch.4.023139 doi:10.1103/PhysRevResearch.4.023139 Close
86.	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
85.	Jingyuan Zhou, Mateusz Zelent, Zhaochu Luo, Valerio Scagnoli, Maciej Krawczyk, Laura J Heyderman, Susmita Saha Precessional dynamics of geometrically scaled magnetostatic spin waves in two-dimensional magnonic fractals Phys. Rev. B, 105 , pp. 174415, 2022. Abstract \| Links \| BibTeX @article{PhysRevB.105.174415, title = {Precessional dynamics of geometrically scaled magnetostatic spin waves in two-dimensional magnonic fractals}, author = {Jingyuan Zhou and Mateusz Zelent and Zhaochu Luo and Valerio Scagnoli and Maciej Krawczyk and Laura J Heyderman and Susmita Saha}, url = {https://link.aps.org/doi/10.1103/PhysRevB.105.174415}, doi = {10.1103/PhysRevB.105.174415}, year = {2022}, date = {2022-05-13}, journal = {Phys. Rev. B}, volume = {105}, pages = {174415}, publisher = {American Physical Society}, abstract = {The control of spin waves in periodic magnetic structures has facilitated the realization of many functional magnonic devices, such as band stop filters and magnonic transistors, where the geometry of the crystal structure plays an important role. Here, we report on the magnetostatic mode formation in an artificial magnetic structure, going beyond the crystal geometry to a fractal structure, where the mode formation is related to the geometric scaling of the fractal structure. Specifically, the precessional dynamics was measured in samples with structures going from simple geometric structures toward a Sierpinski carpet and a Sierpinski triangle. The experimentally observed evolution of the precessional motion could be linked to the progression in the geometric structures that results in a modification of the demagnetizing field. Furthermore, we have found sets of modes at the ferromagnetic resonance frequency that form a scaled spatial distribution following the geometric scaling. Based on this, we have determined the two conditions for such mode formation to occur. One condition is that the associated magnetic boundaries must scale accordingly, and the other condition is that the region where the mode occurs must not coincide with the regions for the edge modes. This established relationship between the fractal geometry and the mode formation in magnetic fractals provides guiding principles for their use in magnonics applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The control of spin waves in periodic magnetic structures has facilitated the realization of many functional magnonic devices, such as band stop filters and magnonic transistors, where the geometry of the crystal structure plays an important role. Here, we report on the magnetostatic mode formation in an artificial magnetic structure, going beyond the crystal geometry to a fractal structure, where the mode formation is related to the geometric scaling of the fractal structure. Specifically, the precessional dynamics was measured in samples with structures going from simple geometric structures toward a Sierpinski carpet and a Sierpinski triangle. The experimentally observed evolution of the precessional motion could be linked to the progression in the geometric structures that results in a modification of the demagnetizing field. Furthermore, we have found sets of modes at the ferromagnetic resonance frequency that form a scaled spatial distribution following the geometric scaling. Based on this, we have determined the two conditions for such mode formation to occur. One condition is that the associated magnetic boundaries must scale accordingly, and the other condition is that the region where the mode occurs must not coincide with the regions for the edge modes. This established relationship between the fractal geometry and the mode formation in magnetic fractals provides guiding principles for their use in magnonics applications. Close https://link.aps.org/doi/10.1103/PhysRevB.105.174415 doi:10.1103/PhysRevB.105.174415 Close
84.	Piotr Majek, Ireneusz Weymann Majorana-Kondo competition in a cross-shaped double quantum dot-topological superconductor system Journal of Magnetism and Magnetic Materials, (549), pp. 168935, 2022. Abstract \| Links \| BibTeX @article{Majek2022, title = {Majorana-Kondo competition in a cross-shaped double quantum dot-topological superconductor system}, author = {Piotr Majek and Ireneusz Weymann}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0304885321011331}, doi = {10.1016/j.jmmm.2021.168935}, year = {2022}, date = {2022-05-01}, journal = {Journal of Magnetism and Magnetic Materials}, number = {549}, pages = {168935}, abstract = {We examine the transport properties of a double quantum dot system coupled to a topological superconducting nanowire hosting Majorana quasiparticles at its ends, with the central quantum dot attached to the left and right leads. We focus on the behavior of the local density of states and the linear conductance, calculated with the aid of the numerical renormalization group method, to describe the influence of the Majorana coupling on the low-temperature transport properties induced by the Kondo correlations. In particular, we show that the presence of Majorana quasiparticles in the system affects both the spin-up and spin-down transport channels, affecting the energy scales associated with the first-stage and second-stage Kondo temperatures, respectively, and modifying the low-energy behavior of the system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We examine the transport properties of a double quantum dot system coupled to a topological superconducting nanowire hosting Majorana quasiparticles at its ends, with the central quantum dot attached to the left and right leads. We focus on the behavior of the local density of states and the linear conductance, calculated with the aid of the numerical renormalization group method, to describe the influence of the Majorana coupling on the low-temperature transport properties induced by the Kondo correlations. In particular, we show that the presence of Majorana quasiparticles in the system affects both the spin-up and spin-down transport channels, affecting the energy scales associated with the first-stage and second-stage Kondo temperatures, respectively, and modifying the low-energy behavior of the system. Close https://www.sciencedirect.com/science/article/abs/pii/S0304885321011331 doi:10.1016/j.jmmm.2021.168935 Close
83.	Paweł Gruszecki, Konstantin Y Guslienko, Igor L Lyubchanskii, Maciej Krawczyk Inelastic Spin-Wave Beam Scattering by Edge-Localized Spin Waves in a Ferromagnetic Thin Film Phys. Rev. Applied, 17 , pp. 044038, 2022. Abstract \| Links \| BibTeX @article{PhysRevApplied.17.044038, title = {Inelastic Spin-Wave Beam Scattering by Edge-Localized Spin Waves in a Ferromagnetic Thin Film}, author = {Paweł Gruszecki and Konstantin Y Guslienko and Igor L Lyubchanskii and Maciej Krawczyk}, url = {https://link.aps.org/doi/10.1103/PhysRevApplied.17.044038}, doi = {10.1103/PhysRevApplied.17.044038}, year = {2022}, date = {2022-04-20}, journal = {Phys. Rev. Applied}, volume = {17}, pages = {044038}, publisher = {American Physical Society}, abstract = {Spin waves are promising chargeless information carriers for the future, energetically efficient beyond CMOS systems. Among many advantages are the ease of achieving nonlinearity, the variety of possible interactions, and excitation types. Although the rapidly developing magnonic research has already yielded impressive realizations, multimode nonlinear effects, particularly with propagating waves and their nanoscale realizations, are still an open research problem.We theoretically study the dynamic interactions of spin waves confined to the edge of a thin ferromagnetic film with the spin-wave beam incident at this edge. We find inelastically scattered spin-wave beams at frequencies increased and decreased by the frequency of the edge spin-wave relative to the specularly reflected beam. We observe a strong dependence of the angular shift of the inelastic scattered spin-wave beam on the edge-mode frequency, which allows us to propose a magnonic demultiplexing of the signal encoded in spin waves propagating along the edge. Since dynamic magnetostatic interactions, which are ubiquitous in the spin-wave dynamics, are decisive in this process, this indicates the possibility of implementing the presented effects in other configurations and their use in magnonic systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Spin waves are promising chargeless information carriers for the future, energetically efficient beyond CMOS systems. Among many advantages are the ease of achieving nonlinearity, the variety of possible interactions, and excitation types. Although the rapidly developing magnonic research has already yielded impressive realizations, multimode nonlinear effects, particularly with propagating waves and their nanoscale realizations, are still an open research problem.We theoretically study the dynamic interactions of spin waves confined to the edge of a thin ferromagnetic film with the spin-wave beam incident at this edge. We find inelastically scattered spin-wave beams at frequencies increased and decreased by the frequency of the edge spin-wave relative to the specularly reflected beam. We observe a strong dependence of the angular shift of the inelastic scattered spin-wave beam on the edge-mode frequency, which allows us to propose a magnonic demultiplexing of the signal encoded in spin waves propagating along the edge. Since dynamic magnetostatic interactions, which are ubiquitous in the spin-wave dynamics, are decisive in this process, this indicates the possibility of implementing the presented effects in other configurations and their use in magnonic systems. Close https://link.aps.org/doi/10.1103/PhysRevApplied.17.044038 doi:10.1103/PhysRevApplied.17.044038 Close
82.	A K Dhiman, R Gieniusz, Paweł Gruszecki, J Kisielewski, M Matczak, Z Kurant, I Sveklo, U Guzowska, M Tekielak, F Stobiecki, A Maziewski Magnetization statics and dynamics in (Ir/Co/Pt)6 multilayers with Dzyaloshinskii–Moriya interaction AIP Advances, 12 (4), pp. 045007, 2022. Abstract \| Links \| BibTeX @article{Dhiman2022DMI, title = {Magnetization statics and dynamics in (Ir/Co/Pt)6 multilayers with Dzyaloshinskii–Moriya interaction}, author = {A K Dhiman and R Gieniusz and Paweł Gruszecki and J Kisielewski and M Matczak and Z Kurant and I Sveklo and U Guzowska and M Tekielak and F Stobiecki and A Maziewski}, doi = {https://doi.org/10.1063/9.0000339}, year = {2022}, date = {2022-04-04}, urldate = {2022-04-04}, journal = {AIP Advances}, volume = {12}, number = {4}, pages = {045007}, abstract = {Magnetic multilayers of (Ir/Co/Pt)6 with interfacial Dzyaloshinskii-Moriya interaction (IDMI) were deposited by magnetron sputtering with Co thickness d=1.8 nm. Exploiting magneto-optical Kerr effect in longitudinal mode microscopy, magnetic force microscopy, and vibrating sample magnetometry, the magnetic field-driven evolution of domain structures and magnetization hysteresis loops have been studied. The existence of weak stripe domains structure was deduced – tens micrometers size domains with in-plane “core” magnetization modulated by hundred of nanometers domains with out-of-plane magnetization. Micromagnetic simulations interpreted such magnetization distribution. Quantitative evaluation of IDMI was carried out using Brillouin light scattering (BLS) spectroscopy as the difference between Stokes and anti-Stokes peak frequencies Δf. Due to the additive nature of IDMI, the asymmetric combination of Ir and Pt covers led to large values of effective IDMI energy density Deff. It was found that Stokes and anti-Stokes frequencies as well as Δf, measured as a function of in-plane applied magnetic field, show hysteresis. These results are explained under the consideration of the influence of IDMI on the dynamics of the in-plane magnetized “core” with weak stripe domains}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnetic multilayers of (Ir/Co/Pt)6 with interfacial Dzyaloshinskii-Moriya interaction (IDMI) were deposited by magnetron sputtering with Co thickness d=1.8 nm. Exploiting magneto-optical Kerr effect in longitudinal mode microscopy, magnetic force microscopy, and vibrating sample magnetometry, the magnetic field-driven evolution of domain structures and magnetization hysteresis loops have been studied. The existence of weak stripe domains structure was deduced – tens micrometers size domains with in-plane “core” magnetization modulated by hundred of nanometers domains with out-of-plane magnetization. Micromagnetic simulations interpreted such magnetization distribution. Quantitative evaluation of IDMI was carried out using Brillouin light scattering (BLS) spectroscopy as the difference between Stokes and anti-Stokes peak frequencies Δf. Due to the additive nature of IDMI, the asymmetric combination of Ir and Pt covers led to large values of effective IDMI energy density Deff. It was found that Stokes and anti-Stokes frequencies as well as Δf, measured as a function of in-plane applied magnetic field, show hysteresis. These results are explained under the consideration of the influence of IDMI on the dynamics of the in-plane magnetized “core” with weak stripe domains Close doi:https://doi.org/10.1063/9.0000339 Close
81.	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
80.	Piotr Trocha, Emil Siuda Spin-thermoelectric effects in a quantum dot hybrid system with magnetic insulator Scientific Reports, 12 (5348), 2022. Abstract \| Links \| BibTeX @article{Trocha2022c, title = {Spin-thermoelectric effects in a quantum dot hybrid system with magnetic insulator}, author = {Piotr Trocha and Emil Siuda}, url = {https://www.nature.com/articles/s41598-022-09105-z}, doi = {10.1038/s41598-022-09105-z}, year = {2022}, date = {2022-03-30}, journal = {Scientific Reports}, volume = {12}, number = {5348}, abstract = {We investigate spin thermoelectric properties of a hybrid system consisting of a single-level quantum dot attached to magnetic insulator and metal electrodes. Magnetic insulator is assumed to be of ferromagnetic type and is a source of magnons, whereas metallic lead is reservoir of electrons. The temperature gradient set between the magnetic insulator and metallic electrodes induces the spin current flowing through the system. The generated spin current of magnonic (electric) type is converted to electric (magnonic) spin current by means of quantum dot. Expanding spin and heat currents flowing through the system, up to linear order, we introduce basic spin thermoelectric coefficients including spin conductance, spin Seebeck and spin Peltier coefficients and heat conductance. We analyse the spin thermoelectric properties of the system in two cases: in the large ondot Coulomb repulsion limit and when these interactions are finite.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We investigate spin thermoelectric properties of a hybrid system consisting of a single-level quantum dot attached to magnetic insulator and metal electrodes. Magnetic insulator is assumed to be of ferromagnetic type and is a source of magnons, whereas metallic lead is reservoir of electrons. The temperature gradient set between the magnetic insulator and metallic electrodes induces the spin current flowing through the system. The generated spin current of magnonic (electric) type is converted to electric (magnonic) spin current by means of quantum dot. Expanding spin and heat currents flowing through the system, up to linear order, we introduce basic spin thermoelectric coefficients including spin conductance, spin Seebeck and spin Peltier coefficients and heat conductance. We analyse the spin thermoelectric properties of the system in two cases: in the large ondot Coulomb repulsion limit and when these interactions are finite. Close https://www.nature.com/articles/s41598-022-09105-z doi:10.1038/s41598-022-09105-z Close
79.	Mir Ali Jafari, Anna Dyrdał First Principle Study on Electronic and Transport Properties of Finite-Length Nanoribbons and Nanodiscs for Selected Two-Dimensional Materials Molecules, 27 (7), pp. 2228, 2022, ISSN: 1420-3049. Abstract \| Links \| BibTeX @article{Jafari2022c, title = {First Principle Study on Electronic and Transport Properties of Finite-Length Nanoribbons and Nanodiscs for Selected Two-Dimensional Materials}, author = {Mir Ali Jafari and Anna Dyrdał}, url = {https://www.mdpi.com/1420-3049/27/7/2228}, doi = {10.3390/molecules27072228}, issn = {1420-3049}, year = {2022}, date = {2022-03-29}, journal = {Molecules}, volume = {27}, number = {7}, pages = {2228}, abstract = {Using the density functional theory, we calculate electronic states of various nanoribbons and nanodiscs formed from selected two-dimensional materials, such as graphene, silicene, and hexagonal boron nitride. The main objective of the analysis is a search for zero-energy states in such systems, which is an important issue as their presence indicates certain topological properties associated with chirality. The analysis is also supported by calculating transport properties.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Using the density functional theory, we calculate electronic states of various nanoribbons and nanodiscs formed from selected two-dimensional materials, such as graphene, silicene, and hexagonal boron nitride. The main objective of the analysis is a search for zero-energy states in such systems, which is an important issue as their presence indicates certain topological properties associated with chirality. The analysis is also supported by calculating transport properties. Close https://www.mdpi.com/1420-3049/27/7/2228 doi:10.3390/molecules27072228 Close
78.	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
77.	Kacper Wrześniewski, Ireneusz Weymann, Nicholas Sedlmayr, Tadeusz Domański Dynamical quantum phase transitions in a mesoscopic superconducting system Phys. Rev. B, 105 , pp. 094514, 2022. Abstract \| Links \| BibTeX @article{Wrześniewski2022c, title = {Dynamical quantum phase transitions in a mesoscopic superconducting system}, author = {Kacper Wrześniewski and Ireneusz Weymann and Nicholas Sedlmayr and Tadeusz Domański}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.094514}, doi = {10.1103/PhysRevB.105.094514}, year = {2022}, date = {2022-03-25}, journal = {Phys. Rev. B}, volume = {105}, pages = {094514}, abstract = {We inspect the signatures of dynamical quantum phase transitions driven by quantum quenches acting on a correlated quantum dot embedded between superconducting and metallic reservoirs. Under stationary conditions, the proximity-induced electron pairing, competing with strong Coulomb repulsion, enforces the quantum dot to be either in the singly occupied or BCS-type ground state, depending on its energy level and coupling to the superconducting lead. By means of the time-dependent numerical renormalization group approach, we study the system's time evolution upon traversing the phase boundary between these two states, examining the Loschmidt echo and revealing nonanalytic features in the low-energy return rate, which signal dynamical quantum phase transitions. We also show that these phase transitions are accompanied by the corresponding local extrema in the pairing correlation function and dot's occupation. Since the proposed quench protocols can be realized in a controllable manner, the detection of this dynamical singlet-doublet phase transition should be feasible by performing tunneling spectroscopy measurements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We inspect the signatures of dynamical quantum phase transitions driven by quantum quenches acting on a correlated quantum dot embedded between superconducting and metallic reservoirs. Under stationary conditions, the proximity-induced electron pairing, competing with strong Coulomb repulsion, enforces the quantum dot to be either in the singly occupied or BCS-type ground state, depending on its energy level and coupling to the superconducting lead. By means of the time-dependent numerical renormalization group approach, we study the system's time evolution upon traversing the phase boundary between these two states, examining the Loschmidt echo and revealing nonanalytic features in the low-energy return rate, which signal dynamical quantum phase transitions. We also show that these phase transitions are accompanied by the corresponding local extrema in the pairing correlation function and dot's occupation. Since the proposed quench protocols can be realized in a controllable manner, the detection of this dynamical singlet-doublet phase transition should be feasible by performing tunneling spectroscopy measurements. Close https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.094514 doi:10.1103/PhysRevB.105.094514 Close
76.	M Baranowski, Sławomir Mamica Resonance modes of periodically structuralized microwave magnetic elements Journal of Magnetism and Magnetic Materials, 553 , pp. 169261, 2022, ISSN: 0304-8853. Abstract \| Links \| BibTeX @article{BARANOWSKI2022169261, title = {Resonance modes of periodically structuralized microwave magnetic elements}, author = {M Baranowski and Sławomir Mamica}, url = {https://www.sciencedirect.com/science/article/pii/S0304885322002128}, doi = {https://doi.org/10.1016/j.jmmm.2022.169261}, issn = {0304-8853}, year = {2022}, date = {2022-03-16}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {553}, pages = {169261}, abstract = {Here we consider a flower-like structure of a resonator consisting of six elliptical elements, referred to as petals, made from a magnetic material. The petals are positioned with their centres at the corners of a regular hexagon. Using numerical simulations (CST Studio) we examine the effect of different radial orientations of petals. We study resonance modes with a specific distribution of the electromagnetic field within the resonator as well as the effect of the rotation of petals on the field distribution. The mode character is crucial to understand the behaviour of the frequency spectrum. E.g., the rotation of petals influences significantly the frequency of the lowest mode only, while the other frequencies are almost unchanged and this effect is directly related to the profiles of modes. The system studied is a promising candidate for a tuneable component of an integrated detection system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Here we consider a flower-like structure of a resonator consisting of six elliptical elements, referred to as petals, made from a magnetic material. The petals are positioned with their centres at the corners of a regular hexagon. Using numerical simulations (CST Studio) we examine the effect of different radial orientations of petals. We study resonance modes with a specific distribution of the electromagnetic field within the resonator as well as the effect of the rotation of petals on the field distribution. The mode character is crucial to understand the behaviour of the frequency spectrum. E.g., the rotation of petals influences significantly the frequency of the lowest mode only, while the other frequencies are almost unchanged and this effect is directly related to the profiles of modes. The system studied is a promising candidate for a tuneable component of an integrated detection system. Close https://www.sciencedirect.com/science/article/pii/S0304885322002128 doi:https://doi.org/10.1016/j.jmmm.2022.169261 Close
75.	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
74.	Piotr Busz, Damian Tomaszewski, Jan Martinek Exchange field determination in a quantum dot spin valve by the spin dynamics Journal of Magnetism and Magnetic Materials, 546 , pp. 168831, 2022. Abstract \| Links \| BibTeX @article{Busz2022, title = {Exchange field determination in a quantum dot spin valve by the spin dynamics}, author = {Piotr Busz and Damian Tomaszewski and Jan Martinek}, url = {https://www.sciencedirect.com/science/article/pii/S0304885321010428}, doi = {10.1016/j.jmmm.2021.168831}, year = {2022}, date = {2022-03-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {546}, pages = {168831}, abstract = {We develop the theory of the electron transport through quantum dot weakly coupled to ferromagnetic leads with noncollinear magnetization directions, that has been studied in recent experiments. One can observe much richer transport behavior of the canted quantum dot spin valves, as compared to single magnetic tunnel junctions, that relies on the possibility to generate a nonequilibrium accumulated spin on the quantum dot and the presence of the exchange interaction between dot and electrodes, depending on system parameters such as gate and bias voltages, the charging energy, an asymmetry of the tunnel couplings, and the external magnetic field. We demonstrate that one can extract information about spin dynamics on quantum dot from the dc current–voltage characteristic even at the linear response, and detect the exchange field similarly to the FMR (ferromagnetic resonance) experiment. This exchange field can be widely used in nano-spinelectronics, as a local field controlled by the gate or bias voltages also at high temperatures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We develop the theory of the electron transport through quantum dot weakly coupled to ferromagnetic leads with noncollinear magnetization directions, that has been studied in recent experiments. One can observe much richer transport behavior of the canted quantum dot spin valves, as compared to single magnetic tunnel junctions, that relies on the possibility to generate a nonequilibrium accumulated spin on the quantum dot and the presence of the exchange interaction between dot and electrodes, depending on system parameters such as gate and bias voltages, the charging energy, an asymmetry of the tunnel couplings, and the external magnetic field. We demonstrate that one can extract information about spin dynamics on quantum dot from the dc current–voltage characteristic even at the linear response, and detect the exchange field similarly to the FMR (ferromagnetic resonance) experiment. This exchange field can be widely used in nano-spinelectronics, as a local field controlled by the gate or bias voltages also at high temperatures. Close https://www.sciencedirect.com/science/article/pii/S0304885321010428 doi:10.1016/j.jmmm.2021.168831 Close
73.	Piotr Trocha, Emil Siuda, Ireneusz Weymann Spin-polarized transport in quadruple quantum dots attached to ferromagnetic leads Journal of Magnetism and Magnetic Materials, 546 (168835), 2022. Abstract \| Links \| BibTeX @article{Trocha2022b, title = {Spin-polarized transport in quadruple quantum dots attached to ferromagnetic leads}, author = {Piotr Trocha and Emil Siuda and Ireneusz Weymann}, url = {https://www.sciencedirect.com/science/article/pii/S0304885321010453}, doi = {10.1016/j.jmmm.2021.168835}, year = {2022}, date = {2022-03-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {546}, number = {168835}, abstract = {Motivated by the experimental evidence of the Nagaoka ferromagnetism in quantum dot systems by Dehollain et al. (2020), we search for possible confirmation of such kind of ferromagnetism by analyzing the spin-resolved transport properties of a quadruple quantum dot system focusing on the linear response regime. In particular, we consider four quantum dots arranged in a two-by-two square lattice, coupled to external ferromagnetic source and drain electrodes. Turning on and off the specific conditions for the Nagaoka ferromagnetism to occur by changing the value of the intra-dot Coulomb interactions, we determine the transport coefficients, including the linear conductance, tunnel magnetoresistance and current spin polarization. We show that a sign change of the current spin polarization may be an indication of a ferromagnetic order of Nagaoka type which develops in the system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Motivated by the experimental evidence of the Nagaoka ferromagnetism in quantum dot systems by Dehollain et al. (2020), we search for possible confirmation of such kind of ferromagnetism by analyzing the spin-resolved transport properties of a quadruple quantum dot system focusing on the linear response regime. In particular, we consider four quantum dots arranged in a two-by-two square lattice, coupled to external ferromagnetic source and drain electrodes. Turning on and off the specific conditions for the Nagaoka ferromagnetism to occur by changing the value of the intra-dot Coulomb interactions, we determine the transport coefficients, including the linear conductance, tunnel magnetoresistance and current spin polarization. We show that a sign change of the current spin polarization may be an indication of a ferromagnetic order of Nagaoka type which develops in the system. Close https://www.sciencedirect.com/science/article/pii/S0304885321010453 doi:10.1016/j.jmmm.2021.168835 Close

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