List of publications
Department of Mesoscopic Physics
Department of Quantum Information
Department of Physics of Nanostructures
Department of Theory of Condensed Matter
2023 |
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192. | Alexandre Huguet, Kacper Wrześniewski, Ireneusz Weymann Spin effects on transport and zero-bias anomaly in a hybrid Majorana wire-quantum dot system Scientific Reports, 13 , pp. 17279, 2023, ISSN: 2045-2322. @article{Huguet2023, title = {Spin effects on transport and zero-bias anomaly in a hybrid Majorana wire-quantum dot system}, author = {Alexandre Huguet and Kacper Wrześniewski and Ireneusz Weymann }, url = {https://www.nature.com/articles/s41598-023-44254-9}, doi = {10.1038/s41598-023-44254-9}, issn = {2045-2322}, year = {2023}, date = {2023-10-12}, journal = {Scientific Reports}, volume = {13}, pages = {17279}, abstract = {We examine the impact of spin effects on the nonequilibrium transport properties of a nanowire hosting Majorana zero-energy modes at its ends, coupled to a quantum dot junction with ferromagnetic leads. Using the real-time diagrammatic technique, we determine the current, differential conductance and current cross-correlations in the nonlinear response regime. We also explore transport in different magnetic configurations of the system, which can be quantified by the tunnel magnetoresistance. We show that the presence of Majorana quasiparticles gives rise to unique features in all spin-resolved transport characteristics, in particular, to zero-bias anomaly, negative differential conductance, negative tunnel magnetoresistance, and it is also reflected in the current cross-correlations. Moreover, we study the dependence of the zero-bias anomaly on various system parameters and demonstrate its dependence on the magnetic configuration of the system as well as on the degree of spin polarization in the leads. A highly nontrivial behavior is also found for the tunnel magnetoresistance, which exhibits regions of enhanced or negative values—new features resulting from the coupling to Majorana wire.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We examine the impact of spin effects on the nonequilibrium transport properties of a nanowire hosting Majorana zero-energy modes at its ends, coupled to a quantum dot junction with ferromagnetic leads. Using the real-time diagrammatic technique, we determine the current, differential conductance and current cross-correlations in the nonlinear response regime. We also explore transport in different magnetic configurations of the system, which can be quantified by the tunnel magnetoresistance. We show that the presence of Majorana quasiparticles gives rise to unique features in all spin-resolved transport characteristics, in particular, to zero-bias anomaly, negative differential conductance, negative tunnel magnetoresistance, and it is also reflected in the current cross-correlations. Moreover, we study the dependence of the zero-bias anomaly on various system parameters and demonstrate its dependence on the magnetic configuration of the system as well as on the degree of spin polarization in the leads. A highly nontrivial behavior is also found for the tunnel magnetoresistance, which exhibits regions of enhanced or negative values—new features resulting from the coupling to Majorana wire. |
191. | Gauthier Philippe, Mathieu Moalic, Jarosław W. Kłos Unidirectional spin wave emission by traveling pair of magnetic field profiles Journal of Magnetism and Magnetic Materials, 587 , pp. 171359, 2023, ISSN: 0304-8853. @article{PHILIPPE2023171359, title = {Unidirectional spin wave emission by traveling pair of magnetic field profiles}, author = {Gauthier Philippe and Mathieu Moalic and Jarosław W. Kłos}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323010090}, doi = {https://doi.org/10.1016/j.jmmm.2023.171359}, issn = {0304-8853}, year = {2023}, date = {2023-10-11}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {587}, pages = {171359}, abstract = {We demonstrate that the spin wave Cherenkov effect can be used to design the unidirectional spin wave emitter with tunable frequency and switchable direction of emission. In our numerical studies, we propose to use a pair of traveling profiles of the magnetic field which generate the spin waves, for sufficiently large velocity of their motion. In the considered system, the spin waves of shorter (longer) wavelengths are induced at the front (back) of the moving profiles and interfere constructively or destructively, depending on the velocity of the profiles. Moreover, we showed that the spin waves can be confined between the pair of traveling profiles of the magnetic field. This work opens the perspectives for the experimental studies in hybrid magnonic-superconducting systems where the magnetic vortices in a superconductor can be used as moving sources of the magnetic field driving the spin waves in the ferromagnetic subsystem.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We demonstrate that the spin wave Cherenkov effect can be used to design the unidirectional spin wave emitter with tunable frequency and switchable direction of emission. In our numerical studies, we propose to use a pair of traveling profiles of the magnetic field which generate the spin waves, for sufficiently large velocity of their motion. In the considered system, the spin waves of shorter (longer) wavelengths are induced at the front (back) of the moving profiles and interfere constructively or destructively, depending on the velocity of the profiles. Moreover, we showed that the spin waves can be confined between the pair of traveling profiles of the magnetic field. This work opens the perspectives for the experimental studies in hybrid magnonic-superconducting systems where the magnetic vortices in a superconductor can be used as moving sources of the magnetic field driving the spin waves in the ferromagnetic subsystem. |
190. | Grzegorz Centała, Jarosław W. Kłos Shaping magnetization dynamics in a planar square dot by adjusting its surface anisotropy Journal of Magnetism and Magnetic Materials, 587 , pp. 171254, 2023, ISSN: 0304-8853. @article{CENTALA2023171254, title = {Shaping magnetization dynamics in a planar square dot by adjusting its surface anisotropy}, author = {Grzegorz Centała and Jarosław W. Kłos}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323009046}, doi = {https://doi.org/10.1016/j.jmmm.2023.171254}, issn = {0304-8853}, year = {2023}, date = {2023-09-22}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {587}, pages = {171254}, abstract = {A planar square dot is one of the simplest structures confined to three dimensions. Despite its geometrical simplicity, the description of the spin wave modes in this structure is not trivial due to the competition of dipolar and exchange interactions. An additional factor that makes this description challenging are the boundary conditions depend both on non-local dipolar interactions and local surface parameters such as surface anisotropy. In the presented work, we showed how the surface anisotropy applied at the lateral faces of the dot can tune the frequency of fundamental mode in the planar CoFeB dot, magnetized in an out-of-plane direction. Moreover, we analyzed the spin wave profile of the fundamental mode and the corresponding dynamic stray field. We showed that the asymmetric application of surface anisotropy produces an asymmetric profile of dynamic stray field for square dot and can be used to tailor inter-dot coupling. The calculations were performed with the use of the finite-element method.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A planar square dot is one of the simplest structures confined to three dimensions. Despite its geometrical simplicity, the description of the spin wave modes in this structure is not trivial due to the competition of dipolar and exchange interactions. An additional factor that makes this description challenging are the boundary conditions depend both on non-local dipolar interactions and local surface parameters such as surface anisotropy. In the presented work, we showed how the surface anisotropy applied at the lateral faces of the dot can tune the frequency of fundamental mode in the planar CoFeB dot, magnetized in an out-of-plane direction. Moreover, we analyzed the spin wave profile of the fundamental mode and the corresponding dynamic stray field. We showed that the asymmetric application of surface anisotropy produces an asymmetric profile of dynamic stray field for square dot and can be used to tailor inter-dot coupling. The calculations were performed with the use of the finite-element method. |
189. | Jan Peřina, Jr., Adam Miranowicz, Joanna K. Kalaga, Wiesław Leoński Unavoidability of nonclassicality loss in PT-symmetric systems Phys. Rev. A, 108 , pp. 033512, 2023. @article{Peřina2023, title = {Unavoidability of nonclassicality loss in PT-symmetric systems}, author = {Jan Peřina, Jr. and Adam Miranowicz and Joanna K. Kalaga and Wiesław Leoński}, url = {https://journals.aps.org/pra/abstract/10.1103/PhysRevA.108.033512}, doi = {10.1103/PhysRevA.108.033512}, year = {2023}, date = {2023-09-15}, journal = {Phys. Rev. A}, volume = {108}, pages = {033512}, abstract = {We show that the loss of nonclassicality (including quantum entanglement) cannot be compensated by the (incoherent) amplification of PT-symmetric systems. We address this problem by manipulating the quantum fluctuating forces in the Heisenberg-Langevin approach. Specifically, we analyze the dynamics of two nonlinearly coupled oscillator modes in a PT-symmetric system. An analytical solution allows us to separate the contribution of reservoir fluctuations from the evolution of quantum statistical properties of the modes. In general, as reservoir fluctuations act constantly, the complete loss of nonclassicality and entanglement is observed for long times. To elucidate the role of reservoir fluctuations in a long-time evolution of nonclassicality and entanglement, we consider and compare the predictions from two alternative models in which no fatal long-time detrimental effects on the nonclassicality and entanglement are observed. This is so as, in the first semiclassical model, no reservoir fluctuations are considered at all. This, however, violates the fluctuation-dissipation theorem. The second, more elaborated, model obeys the fluctuation-dissipation relations as it partly involves reservoir fluctuations. However, to prevent the above long-time detrimental effects, the reservoir fluctuations have to be endowed with the nonphysical properties of a sink model. In both models, additional incorporation of the omitted reservoir fluctuations results in their physically consistent behavior. This behavior, however, predicts the gradual loss of the nonclassicality and entanglement. Thus the effects of reservoir fluctuations related to damping cannot be compensated by those related to amplification. This qualitatively differs from the influence of damping and amplification to a direct coherent dynamics of PT-symmetric systems in which their mutual interference results in a periodic behavior allowing for nonclassicality and entanglement at arbitrary times.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We show that the loss of nonclassicality (including quantum entanglement) cannot be compensated by the (incoherent) amplification of PT-symmetric systems. We address this problem by manipulating the quantum fluctuating forces in the Heisenberg-Langevin approach. Specifically, we analyze the dynamics of two nonlinearly coupled oscillator modes in a PT-symmetric system. An analytical solution allows us to separate the contribution of reservoir fluctuations from the evolution of quantum statistical properties of the modes. In general, as reservoir fluctuations act constantly, the complete loss of nonclassicality and entanglement is observed for long times. To elucidate the role of reservoir fluctuations in a long-time evolution of nonclassicality and entanglement, we consider and compare the predictions from two alternative models in which no fatal long-time detrimental effects on the nonclassicality and entanglement are observed. This is so as, in the first semiclassical model, no reservoir fluctuations are considered at all. This, however, violates the fluctuation-dissipation theorem. The second, more elaborated, model obeys the fluctuation-dissipation relations as it partly involves reservoir fluctuations. However, to prevent the above long-time detrimental effects, the reservoir fluctuations have to be endowed with the nonphysical properties of a sink model. In both models, additional incorporation of the omitted reservoir fluctuations results in their physically consistent behavior. This behavior, however, predicts the gradual loss of the nonclassicality and entanglement. Thus the effects of reservoir fluctuations related to damping cannot be compensated by those related to amplification. This qualitatively differs from the influence of damping and amplification to a direct coherent dynamics of PT-symmetric systems in which their mutual interference results in a periodic behavior allowing for nonclassicality and entanglement at arbitrary times. |
188. | Jolanta Natalia Latosińska, Magdalena Latosińska, Janez Seliger, Veselko Žagar Processes, 11 (9), 2023, ISSN: 2227-9717. @article{pr11092740, title = {Exploring Partial Structural Disorder in Anhydrous Paraxanthine through Combined Experiment, Solid-State Computational Modelling, and Molecular Docking}, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Janez Seliger and Veselko Žagar}, url = {https://www.mdpi.com/2227-9717/11/9/2740}, doi = {10.3390/pr11092740}, issn = {2227-9717}, year = {2023}, date = {2023-09-14}, journal = {Processes}, volume = {11}, number = {9}, abstract = {Paraxanthine (PX), a major metabolite of caffeine, a protective agent against Alzheimer’s and Parkinson’s disease, and a promising drug for the treatment of post-COVID 2019 anosmia and ageusia, has been studied in the solid state and protein–ligand complex. Partial disorder in PX, caused by the methyl group at the N(7) position, has been modelled and discussed. The relationship between the unusual structural disorder and the propensity to form a specific system of non-covalent bonds was analyzed. Three 1H-14N NMR-NQR (nuclear magnetic resonance–nuclear quadrupole resonance) experimental techniques were used, namely multiple frequency sweeps, Larmor frequency scanning, and the two-frequency irradiation, followed by solid-state computational modelling (density functional theory, supplemented by quantum theory of atoms in molecules, 3D Hirshfeld surfaces, and reduced density gradient), and molecular docking approaches. New quantitative methods for estimating changes in the global pattern of interactions under the influence of rotation of the methyl group in N(7) based on the Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance have been proposed and applied. A spectrum consisting of 12 lines, indicating the presence of 4 chemically inequivalent nitrogen sites in the PX molecule, was recorded, and the lines’ assignment to particular sites was made. The influence of the methyl rotation on the eigenvalues and eigenvectors of the electric field gradient tensor, NQR parameters, and resonance line positions was modelled in the solid (GGA/RPBE, m-GGA/RSCAN) and cluster (Minnesota M062X hybrid). Three factors have been found to determine structural disorder in PX: larger crystal voids near the methyl at N(7) than at N(1) (opening the path for the disorder), hyperconjugation strongly affecting the density distribution in the five-membered ring, and the involvement of the methyl group at N(7) in many non-covalent bonds that intercept (capture) subsequent jumping protons. The Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance confirmed the changes in the distribution and strength of non-covalent interactions throughout the molecule as a result of methyl rotation. This effect is clearly visible regardless of the type of metric, and its order of magnitude is consistent with the modulation effect of the NQR spectra (experimental and calculated). Through molecular docking, it was discovered that the PX moiety in protein–ligand complexes adopt the same methyl group conformation at N(7) as in the solid state. It was found that the cooperation–competition between the C-H⋯O hydrogen bonds and C-H⋯H-C dispersion interactions is the crucial factor that impedes methyl rotation and induces structural disorder, as well as being an important factor in the formation of the protein–ligand complexes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Paraxanthine (PX), a major metabolite of caffeine, a protective agent against Alzheimer’s and Parkinson’s disease, and a promising drug for the treatment of post-COVID 2019 anosmia and ageusia, has been studied in the solid state and protein–ligand complex. Partial disorder in PX, caused by the methyl group at the N(7) position, has been modelled and discussed. The relationship between the unusual structural disorder and the propensity to form a specific system of non-covalent bonds was analyzed. Three 1H-14N NMR-NQR (nuclear magnetic resonance–nuclear quadrupole resonance) experimental techniques were used, namely multiple frequency sweeps, Larmor frequency scanning, and the two-frequency irradiation, followed by solid-state computational modelling (density functional theory, supplemented by quantum theory of atoms in molecules, 3D Hirshfeld surfaces, and reduced density gradient), and molecular docking approaches. New quantitative methods for estimating changes in the global pattern of interactions under the influence of rotation of the methyl group in N(7) based on the Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance have been proposed and applied. A spectrum consisting of 12 lines, indicating the presence of 4 chemically inequivalent nitrogen sites in the PX molecule, was recorded, and the lines’ assignment to particular sites was made. The influence of the methyl rotation on the eigenvalues and eigenvectors of the electric field gradient tensor, NQR parameters, and resonance line positions was modelled in the solid (GGA/RPBE, m-GGA/RSCAN) and cluster (Minnesota M062X hybrid). Three factors have been found to determine structural disorder in PX: larger crystal voids near the methyl at N(7) than at N(1) (opening the path for the disorder), hyperconjugation strongly affecting the density distribution in the five-membered ring, and the involvement of the methyl group at N(7) in many non-covalent bonds that intercept (capture) subsequent jumping protons. The Pompeiu–Hausdorff and Bhattacharayya metrics and the Wasserstein distance confirmed the changes in the distribution and strength of non-covalent interactions throughout the molecule as a result of methyl rotation. This effect is clearly visible regardless of the type of metric, and its order of magnitude is consistent with the modulation effect of the NQR spectra (experimental and calculated). Through molecular docking, it was discovered that the PX moiety in protein–ligand complexes adopt the same methyl group conformation at N(7) as in the solid state. It was found that the cooperation–competition between the C-H⋯O hydrogen bonds and C-H⋯H-C dispersion interactions is the crucial factor that impedes methyl rotation and induces structural disorder, as well as being an important factor in the formation of the protein–ligand complexes. |
187. | Ri-Hua Zheng, Wen Ning, Ye-Hong Chen, Jia-Hao Lü, Li-Tuo Shen, Kai Xu, Yu-Ran Zhang, Da Xu, Hekang Li, Yan Xia, Fan Wu, Zhen-Biao Yang, Adam Miranowicz, Neill Lambert, Dongning Zheng, Heng Fan, Franco Nori, Shi-Biao Zheng Observation of a Superradiant Phase Transition with Emergent Cat States Phys. Rev. Lett., 131 , pp. 113601 , 2023. @article{Zheng2023, title = {Observation of a Superradiant Phase Transition with Emergent Cat States}, author = {Ri-Hua Zheng and Wen Ning and Ye-Hong Chen and Jia-Hao Lü and Li-Tuo Shen and Kai Xu and Yu-Ran Zhang and Da Xu and Hekang Li and Yan Xia and Fan Wu and Zhen-Biao Yang and Adam Miranowicz and Neill Lambert and Dongning Zheng and Heng Fan and Franco Nori and Shi-Biao Zheng}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.113601}, doi = {10.1103/PhysRevLett.131.113601}, year = {2023}, date = {2023-09-11}, journal = {Phys. Rev. Lett.}, volume = {131}, pages = {113601 }, abstract = {Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level, and play a central role in criticality-enhanced quantum sensing. So far, SPTs have been observed in driven-dissipative systems, but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic mesoscopic superposition, and reveal light-matter entanglement.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level, and play a central role in criticality-enhanced quantum sensing. So far, SPTs have been observed in driven-dissipative systems, but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic mesoscopic superposition, and reveal light-matter entanglement. |
186. | Sreedevi Janardhanan, Sławomir Mielcarek, Piotr Kuświk, Maciej Krawczyk, Aleksandra Trzaskowska High-resolution Brillouin light scattering study on Ti/Au/Co/Ni multilayer Journal of Magnetism and Magnetic Materials, 586 , pp. 171209, 2023, ISSN: 0304-8853. @article{JANARDHANAN2023171209, title = {High-resolution Brillouin light scattering study on Ti/Au/Co/Ni multilayer}, author = {Sreedevi Janardhanan and Sławomir Mielcarek and Piotr Kuświk and Maciej Krawczyk and Aleksandra Trzaskowska}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323008594}, doi = {https://doi.org/10.1016/j.jmmm.2023.171209}, issn = {0304-8853}, year = {2023}, date = {2023-09-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {586}, pages = {171209}, abstract = {The topic of this paper addresses the Brillouin light scattering (BLS) study of the spin-wave and surface acoustic wave dynamics in the multilayer consisting of Ti/Au/Co/Ni deposited on Si substrate. We make the quantitative analysis of spin-wave frequency under a range of wave vectors to determine the dispersion relation and to study the effect of the magnetic field. These findings were correlated with theoretical models to determine the magnetic system parameters, such as magnetization, Lande g factor, exchange stiffness constant etc. In addition to this, we have conducted finite element method based simulations to understand the nature of surface phonons and to determine the elastic tensor parameters for the Ti/Au/Co/Ni layer from the fitting of simulation results with the experiment data points.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The topic of this paper addresses the Brillouin light scattering (BLS) study of the spin-wave and surface acoustic wave dynamics in the multilayer consisting of Ti/Au/Co/Ni deposited on Si substrate. We make the quantitative analysis of spin-wave frequency under a range of wave vectors to determine the dispersion relation and to study the effect of the magnetic field. These findings were correlated with theoretical models to determine the magnetic system parameters, such as magnetization, Lande g factor, exchange stiffness constant etc. In addition to this, we have conducted finite element method based simulations to understand the nature of surface phonons and to determine the elastic tensor parameters for the Ti/Au/Co/Ni layer from the fitting of simulation results with the experiment data points. |
185. | Mateusz Zelent, Mathieu Moalic, Michal Mruczkiewicz, Xiaoguang Li, Yan Zhou, Maciej Krawczyk Stabilization and racetrack application of asymmetric Néel skyrmions in hybrid nanostructures Scientific Reports, 13 (1), pp. 13572, 2023, ISSN: 2045-2322. @article{zelent_stabilization_2023, title = {Stabilization and racetrack application of asymmetric Néel skyrmions in hybrid nanostructures}, author = {Mateusz Zelent and Mathieu Moalic and Michal Mruczkiewicz and Xiaoguang Li and Yan Zhou and Maciej Krawczyk}, url = {https://www.nature.com/articles/s41598-023-40236-z}, doi = {10.1038/s41598-023-40236-z}, issn = {2045-2322}, year = {2023}, date = {2023-08-21}, urldate = {2023-08-24}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {13572}, abstract = {Magnetic skyrmions, topological quasiparticles, are small stable magnetic textures that possess intriguing properties and potential for data storage applications. Hybrid nanostructures comprised of skyrmions and soft magnetic material can offer additional advantages for developing skyrmion-based spintronic and magnonic devices. We show that a Néel-type skyrmion confined within a nanodot placed on top of a ferromagnetic in-plane magnetized stripe produces a unique and compelling platform for exploring the mutual coupling between magnetization textures. The skyrmion induces an imprint upon the stripe, which, in turn, asymmetrically squeezes the skyrmion in the dot, increasing their size and the range of skyrmion stability at small values of Dzyaloshinskii–Moriya interaction, as well as introducing skyrmion bi-stability. Finally, by exploiting the properties of the skyrmion in a hybrid system, we demonstrate unlimited skyrmion transport along a racetrack, free of the skyrmion Hall effect.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Magnetic skyrmions, topological quasiparticles, are small stable magnetic textures that possess intriguing properties and potential for data storage applications. Hybrid nanostructures comprised of skyrmions and soft magnetic material can offer additional advantages for developing skyrmion-based spintronic and magnonic devices. We show that a Néel-type skyrmion confined within a nanodot placed on top of a ferromagnetic in-plane magnetized stripe produces a unique and compelling platform for exploring the mutual coupling between magnetization textures. The skyrmion induces an imprint upon the stripe, which, in turn, asymmetrically squeezes the skyrmion in the dot, increasing their size and the range of skyrmion stability at small values of Dzyaloshinskii–Moriya interaction, as well as introducing skyrmion bi-stability. Finally, by exploiting the properties of the skyrmion in a hybrid system, we demonstrate unlimited skyrmion transport along a racetrack, free of the skyrmion Hall effect. |
184. | Victor A L'vov, Yulia Kharlan, Vladimir O Golub Nonrelaxational FMR peak broadening in spatially inhomogeneous films Journal of Magnetism and Magnetic Materials, 580 , pp. 170906, 2023, ISSN: 0304-8853. @article{LVOV2023170906, title = {Nonrelaxational FMR peak broadening in spatially inhomogeneous films}, author = {Victor A L'vov and Yulia Kharlan and Vladimir O Golub}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323005565}, doi = {https://doi.org/10.1016/j.jmmm.2023.170906}, issn = {0304-8853}, year = {2023}, date = {2023-08-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {580}, pages = {170906}, abstract = {The modification of magnetic properties in spatially inhomogeneous epitaxial films of magnetic shape memory alloys in martensitic state with the temperature variation has been studied. The proposed theoretical model is based on Landau theory of martensitic transformation and statistical model of martensitic state. It was shown that that spatial inhomogeneity of the material leads to the dispersion of local martensitic transformation temperatures resulting in the variation of local magnetic anisotropy values. This model allows describing the dramatic ferromagnetic resonance line broadening observed in the experiments in epitaxial films of magnetic shape memory alloys at low temperatures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The modification of magnetic properties in spatially inhomogeneous epitaxial films of magnetic shape memory alloys in martensitic state with the temperature variation has been studied. The proposed theoretical model is based on Landau theory of martensitic transformation and statistical model of martensitic state. It was shown that that spatial inhomogeneity of the material leads to the dispersion of local martensitic transformation temperatures resulting in the variation of local magnetic anisotropy values. This model allows describing the dramatic ferromagnetic resonance line broadening observed in the experiments in epitaxial films of magnetic shape memory alloys at low temperatures. |
183. | Karol Bartkiewicz, Patrycja Tulewicz, Jan Roik, Karel Lemr Synergic quantum generative machine learning Scientific Reports, 13 (1), pp. 12893, 2023, ISSN: 2045-2322. @article{bartkiewicz_synergic_2023, title = {Synergic quantum generative machine learning}, author = {Karol Bartkiewicz and Patrycja Tulewicz and Jan Roik and Karel Lemr}, url = {https://www.nature.com/articles/s41598-023-40137-1}, doi = {10.1038/s41598-023-40137-1}, issn = {2045-2322}, year = {2023}, date = {2023-08-09}, urldate = {2023-10-18}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {12893}, abstract = {We introduce a new approach towards generative quantum machine learning significantly reducing the number of hyperparameters and report on a proof-of-principle experiment demonstrating our approach. Our proposal depends on collaboration between the generators and discriminator, thus, we call it quantum synergic generative learning. We present numerical evidence that the synergic approach, in some cases, compares favorably to recently proposed quantum generative adversarial learning. In addition to the results obtained with quantum simulators, we also present experimental results obtained with an actual programmable quantum computer. We investigate how a quantum computer implementing generative learning algorithm could learn the concept of a maximally-entangled state. After completing the learning process, the network is able both to recognize and to generate an entangled state. Our approach can be treated as one possible preliminary step to understanding how the concept of quantum entanglement can be learned and demonstrated by a quantum computer.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We introduce a new approach towards generative quantum machine learning significantly reducing the number of hyperparameters and report on a proof-of-principle experiment demonstrating our approach. Our proposal depends on collaboration between the generators and discriminator, thus, we call it quantum synergic generative learning. We present numerical evidence that the synergic approach, in some cases, compares favorably to recently proposed quantum generative adversarial learning. In addition to the results obtained with quantum simulators, we also present experimental results obtained with an actual programmable quantum computer. We investigate how a quantum computer implementing generative learning algorithm could learn the concept of a maximally-entangled state. After completing the learning process, the network is able both to recognize and to generate an entangled state. Our approach can be treated as one possible preliminary step to understanding how the concept of quantum entanglement can be learned and demonstrated by a quantum computer. |
182. | Grzegorz Centała, Jarosław W. Kłos Compact localized states in magnonic Lieb lattices Scientific Reports, 13 (1), pp. 12676, 2023, ISSN: 2045-2322. @article{centala_compact_2023, title = {Compact localized states in magnonic Lieb lattices}, author = {Grzegorz Centała and Jarosław W. Kłos}, url = {https://www.nature.com/articles/s41598-023-39816-w}, doi = {10.1038/s41598-023-39816-w}, issn = {2045-2322}, year = {2023}, date = {2023-08-04}, urldate = {2023-08-04}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {12676}, abstract = {Lieb lattice is one of the simplest bipartite lattices, where compact localized states (CLS) are observed. This type of localization is induced by the peculiar topology of the unit cell, where the modes are localized only on selected sublattices due to the destructive interference of partial waves. We demonstrate the possibility of magnonic Lieb lattice realization, where flat bands and CLS can be observed in the planar structure of sub-micron in-plane sizes. Using forward volume configuration, the Ga-doped YIG layer with cylindrical inclusions (without Ga content) arranged in a Lieb lattice with 250 nm period was investigated numerically (finite-element method). The structure was tailored to observe, for a lowest magnonic bands, the oscillatory and evanescent spin waves in inclusions and matrix, respectively. Such a design reproduces the Lieb lattice of nodes (inclusions) coupled to each other by the matrix with the CLS in flat bands.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Lieb lattice is one of the simplest bipartite lattices, where compact localized states (CLS) are observed. This type of localization is induced by the peculiar topology of the unit cell, where the modes are localized only on selected sublattices due to the destructive interference of partial waves. We demonstrate the possibility of magnonic Lieb lattice realization, where flat bands and CLS can be observed in the planar structure of sub-micron in-plane sizes. Using forward volume configuration, the Ga-doped YIG layer with cylindrical inclusions (without Ga content) arranged in a Lieb lattice with 250 nm period was investigated numerically (finite-element method). The structure was tailored to observe, for a lowest magnonic bands, the oscillatory and evanescent spin waves in inclusions and matrix, respectively. Such a design reproduces the Lieb lattice of nodes (inclusions) coupled to each other by the matrix with the CLS in flat bands. |
181. | Krzysztof Sobucki, Wojciech Śmigaj, Piotr Graczyk, Maciej Krawczyk, Paweł Gruszecki Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood’s Anomaly Nano Letters, 23 (15), pp. 6979-6984, 2023, (PMID: 37523860). @article{doi:10.1021/acs.nanolett.3c01592, title = {Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood’s Anomaly}, author = {Krzysztof Sobucki and Wojciech Śmigaj and Piotr Graczyk and Maciej Krawczyk and Paweł Gruszecki}, url = {https://doi.org/10.1021/acs.nanolett.3c01592}, doi = {10.1021/acs.nanolett.3c01592}, year = {2023}, date = {2023-07-31}, journal = {Nano Letters}, volume = {23}, number = {15}, pages = {6979-6984}, abstract = {We demonstrate numerically how a spin wave (SW) beam obliquely incident on the edge of a thin film placed below a ferromagnetic stripe can excite leaky SWs guided along the stripe. During propagation, leaky waves emit energy back into the layer in the form of plane waves and several laterally shifted parallel SW beams. This resonance excitation, combined with interference effects of the reflected and re-emitted waves, results in the magnonic Wood’s anomaly and a significant increase of the Goos-Hänchen shift magnitude. This yields a unique platform to control SW reflection and transdimensional magnonic router that can transfer SWs from a 2D platform into a 1D guided mode.}, note = {PMID: 37523860}, keywords = {}, pubstate = {published}, tppubtype = {article} } We demonstrate numerically how a spin wave (SW) beam obliquely incident on the edge of a thin film placed below a ferromagnetic stripe can excite leaky SWs guided along the stripe. During propagation, leaky waves emit energy back into the layer in the form of plane waves and several laterally shifted parallel SW beams. This resonance excitation, combined with interference effects of the reflected and re-emitted waves, results in the magnonic Wood’s anomaly and a significant increase of the Goos-Hänchen shift magnitude. This yields a unique platform to control SW reflection and transdimensional magnonic router that can transfer SWs from a 2D platform into a 1D guided mode. |
180. | Uladzislau Makartsou, Mathieu Moalic, Mateusz Zelent, Michal Mruczkiewicz, Maciej Krawczyk Control of vortex chirality in a symmetric ferromagnetic ring using a ferromagnetic nanoelement Nanoscale, pp. -, 2023. @article{D3NR00582H, title = {Control of vortex chirality in a symmetric ferromagnetic ring using a ferromagnetic nanoelement}, author = {Uladzislau Makartsou and Mathieu Moalic and Mateusz Zelent and Michal Mruczkiewicz and Maciej Krawczyk}, url = {http://dx.doi.org/10.1039/D3NR00582H}, doi = {10.1039/D3NR00582H}, year = {2023}, date = {2023-07-27}, journal = {Nanoscale}, pages = {-}, publisher = {The Royal Society of Chemistry}, abstract = {Controlling the vortex chirality in ferromagnetic nanodots and nanorings has been a topic of investigation for the last few years. Many control methods have been proposed and it has been found that the control is related to the breaking of the circular symmetry of the ring. In this paper, we present a theoretical study demonstrating the control of chirality in a symmetrical ferromagnetic nanoring by breaking the circular symmetry of the system by placing an elongated ferromagnetic nanoelement inside the ring. Here, the stray magnetostatic field exerted by the asymmetrically placed nanoelement determines the movement of the domain walls upon re-magnetization of the nanoring and the resulting chirality in remanence. Thus, the use of a nanoelement not only allows control of the chirality of the vortex state in an isolated ring, but also offers an opportunity to control magnetization in denser nanoring systems, as well as for spintronic and magnonic applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Controlling the vortex chirality in ferromagnetic nanodots and nanorings has been a topic of investigation for the last few years. Many control methods have been proposed and it has been found that the control is related to the breaking of the circular symmetry of the ring. In this paper, we present a theoretical study demonstrating the control of chirality in a symmetrical ferromagnetic nanoring by breaking the circular symmetry of the system by placing an elongated ferromagnetic nanoelement inside the ring. Here, the stray magnetostatic field exerted by the asymmetrically placed nanoelement determines the movement of the domain walls upon re-magnetization of the nanoring and the resulting chirality in remanence. Thus, the use of a nanoelement not only allows control of the chirality of the vortex state in an isolated ring, but also offers an opportunity to control magnetization in denser nanoring systems, as well as for spintronic and magnonic applications. |
179. | Anna Dyrdał, Alireza Qaiumzadeh, Arne Brataas, Józef Barnaś Magnon-plasmon hybridization mediated by spin-orbit interaction in magnetic materials Physical Review B, 108 (4), pp. 045414, 2023. @article{Dyrdał2023, title = {Magnon-plasmon hybridization mediated by spin-orbit interaction in magnetic materials}, author = {Anna Dyrdał and Alireza Qaiumzadeh and Arne Brataas and Józef Barnaś}, url = {https://doi.org/10.1103/PhysRevB.108.045414}, doi = {10.1103/PhysRevB.108.045414}, year = {2023}, date = {2023-07-21}, journal = {Physical Review B}, volume = {108}, number = {4}, pages = {045414}, abstract = {We propose a mechanism for magnon-plasmon coupling and hybridization in ferromagnetic (FM) and antiferromagnetic (AFM) systems. The electric field associated with plasmon oscillations creates a nonequilibrium spin density via the inverse spin galvanic effect. This plasmon-induced spin density couples to magnons by an exchange interaction. The strength of magnon-plasmon coupling depends on the magnetoelectric susceptibility of the system and the wavevector at which the level repulsion has happened. This wavevector may be tuned by an applied magnetic field. In AFM systems, the degeneracy of two chiral magnons is broken in the presence of a magnetic field, and we find two separate hybrid modes for left-handed and right-handed AFM magnons. Furthermore, we show that magnon-plasmon coupling in AFM systems is enhanced because of strong intrasublattice spin dynamics. We argue that the recently discovered two-dimensional magnetic systems are ideal platforms to investigate proposed magnon-plasmon hybrid modes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We propose a mechanism for magnon-plasmon coupling and hybridization in ferromagnetic (FM) and antiferromagnetic (AFM) systems. The electric field associated with plasmon oscillations creates a nonequilibrium spin density via the inverse spin galvanic effect. This plasmon-induced spin density couples to magnons by an exchange interaction. The strength of magnon-plasmon coupling depends on the magnetoelectric susceptibility of the system and the wavevector at which the level repulsion has happened. This wavevector may be tuned by an applied magnetic field. In AFM systems, the degeneracy of two chiral magnons is broken in the presence of a magnetic field, and we find two separate hybrid modes for left-handed and right-handed AFM magnons. Furthermore, we show that magnon-plasmon coupling in AFM systems is enhanced because of strong intrasublattice spin dynamics. We argue that the recently discovered two-dimensional magnetic systems are ideal platforms to investigate proposed magnon-plasmon hybrid modes. |
178. | V. Bilokon, E. Bilokon, M. C. Bañuls, Agnieszka Cichy, A. Sotnikov Many-body correlations in one-dimensional optical lattices with alkaline-earth(-like) atoms Scientific Reports, 13 , pp. 9857, 2023. @article{Bilokon2023, title = {Many-body correlations in one-dimensional optical lattices with alkaline-earth(-like) atoms}, author = {V. Bilokon and E. Bilokon and M. C. Bañuls and Agnieszka Cichy and A. Sotnikov}, doi = {10.1038/s41598-023-37077-1}, year = {2023}, date = {2023-07-17}, journal = {Scientific Reports}, volume = {13}, pages = {9857}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
177. | Wojciech Śmigaj, Krzysztof Sobucki, Paweł Gruszecki, Maciej Krawczyk Modal approach to modeling spin wave scattering Phys. Rev. B, 108 , pp. 014418, 2023. @article{PhysRevB.108.014418, title = {Modal approach to modeling spin wave scattering}, author = {Wojciech Śmigaj and Krzysztof Sobucki and Paweł Gruszecki and Maciej Krawczyk}, url = {https://link.aps.org/doi/10.1103/PhysRevB.108.014418}, doi = {10.1103/PhysRevB.108.014418}, year = {2023}, date = {2023-07-01}, journal = {Phys. Rev. B}, volume = {108}, pages = {014418}, publisher = {American Physical Society}, abstract = {Efficient numerical methods are required for the design of optimized devices. In magnonics, the primary computational tool is micromagnetic simulations, which solve the Landau-Lifshitz equation discretized in time and space. However, their computational cost is high, and the complexity of their output hinders insight into the physics of the simulated system, especially in the case of multimode propagating-wave-based devices. We propose a finite-element modal method allowing an efficient solution of the scattering problem for dipole-exchange spin waves propagating perpendicularly to the magnetization direction. The method gives direct access to the scattering matrix of the whole system and its components. We extend the formula for the power carried by a magnetostatic mode in the Damon-Eshbach configuration to the case with exchange, allowing the scattering coefficients to be normalized to represent the fraction of the input power transferred to each output channel. We apply the method to the analysis of spin wave scattering on a basic functional block of magnonic circuits, consisting of a resonator dynamically coupled to a thin film. The results and the method are validated by comparison with micromagnetic simulations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Efficient numerical methods are required for the design of optimized devices. In magnonics, the primary computational tool is micromagnetic simulations, which solve the Landau-Lifshitz equation discretized in time and space. However, their computational cost is high, and the complexity of their output hinders insight into the physics of the simulated system, especially in the case of multimode propagating-wave-based devices. We propose a finite-element modal method allowing an efficient solution of the scattering problem for dipole-exchange spin waves propagating perpendicularly to the magnetization direction. The method gives direct access to the scattering matrix of the whole system and its components. We extend the formula for the power carried by a magnetostatic mode in the Damon-Eshbach configuration to the case with exchange, allowing the scattering coefficients to be normalized to represent the fraction of the input power transferred to each output channel. We apply the method to the analysis of spin wave scattering on a basic functional block of magnonic circuits, consisting of a resonator dynamically coupled to a thin film. The results and the method are validated by comparison with micromagnetic simulations. |
176. | Andrzej Grudka, Paweł Kurzyński, Tomasz P Polak, Adam S Sajna, Jan Wójcik, Antoni Wójcik Complementarity in quantum walks Journal of Physics A, 56 , pp. 275303, 2023. @article{grudka23-2, title = {Complementarity in quantum walks}, author = {Andrzej Grudka and Paweł Kurzyński and Tomasz P Polak and Adam S Sajna and Jan Wójcik and Antoni Wójcik}, doi = {10.1088/1751-8121/acdcd0}, year = {2023}, date = {2023-06-19}, journal = {Journal of Physics A}, volume = {56}, pages = {275303}, abstract = {The eigenbases of two quantum observables, {|ai⟩}Di=1 and {|bj⟩}Dj=1, form mutually unbiased bases (MUB) if |⟨ai |bj⟩| = 1/ √D for all i and j. In realistic situations MUB are hard to obtain and one looks for approximate MUB (AMUB), in which case the corresponding eigenbases obey |⟨ai |bj⟩| ⩽ c/√D, where c is some positive constant independent of D. In majority of cases observables corresponding to MUB and AMUB do not have clear physical interpretation. Here we study discrete-time quantum walks (QWs) on d-cycles with a position and coin-dependent phase-shift. Such a model simulates a dynamics of a quantum particle moving on a ring with an artificial gauge field. In our case the amplitude of the phase-shift is governed by a single discrete parameter q. We solve the model analytically and observe that for prime d the eigenvectors of two QW evolution operators form AMUB. Namely, if d is prime the corresponding eigenvectors of the evolution operators, that act in the D-dimensional Hilbert space (D = 2d), obey |⟨vq|v ′q ′ ⟩| ⩽√2/√D for q ̸= q ′ and for all |vq⟩ and |v ′q ′ ⟩. Finally, we show that the analogous AMUB relation still holds in the continuous version of this model, which corresponds to a one-dimensional Dirac particle.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The eigenbases of two quantum observables, {|ai⟩}Di=1 and {|bj⟩}Dj=1, form mutually unbiased bases (MUB) if |⟨ai |bj⟩| = 1/ √D for all i and j. In realistic situations MUB are hard to obtain and one looks for approximate MUB (AMUB), in which case the corresponding eigenbases obey |⟨ai |bj⟩| ⩽ c/√D, where c is some positive constant independent of D. In majority of cases observables corresponding to MUB and AMUB do not have clear physical interpretation. Here we study discrete-time quantum walks (QWs) on d-cycles with a position and coin-dependent phase-shift. Such a model simulates a dynamics of a quantum particle moving on a ring with an artificial gauge field. In our case the amplitude of the phase-shift is governed by a single discrete parameter q. We solve the model analytically and observe that for prime d the eigenvectors of two QW evolution operators form AMUB. Namely, if d is prime the corresponding eigenvectors of the evolution operators, that act in the D-dimensional Hilbert space (D = 2d), obey |⟨vq|v ′q ′ ⟩| ⩽√2/√D for q ̸= q ′ and for all |vq⟩ and |v ′q ′ ⟩. Finally, we show that the analogous AMUB relation still holds in the continuous version of this model, which corresponds to a one-dimensional Dirac particle. |
175. | Mateusz Gołębiewski, Hanna Reshetniak, Uladzislau Makartsou, Maciej Krawczyk, Arjen van den Berg, Sam Ladak, Anjan Barman Spin-Wave Spectral Analysis in Crescent-Shaped Ferromagnetic Nanorods Phys. Rev. Appl., 19 , pp. 064045, 2023. @article{PhysRevApplied.19.064045, title = {Spin-Wave Spectral Analysis in Crescent-Shaped Ferromagnetic Nanorods}, author = {Mateusz Gołębiewski and Hanna Reshetniak and Uladzislau Makartsou and Maciej Krawczyk and Arjen van den Berg and Sam Ladak and Anjan Barman}, url = {https://link.aps.org/doi/10.1103/PhysRevApplied.19.064045}, doi = {10.1103/PhysRevApplied.19.064045}, year = {2023}, date = {2023-06-14}, journal = {Phys. Rev. Appl.}, volume = {19}, pages = {064045}, publisher = {American Physical Society}, abstract = {The research on the properties of spin waves (SWs) in three-dimensional nanosystems is an innovative idea in the field of magnonics. Mastering and understanding the nature of magnetization dynamics and binding of SWs at surfaces, edges, and in-volume parts of three-dimensional magnetic systems enables the discovery of alternative phenomena and suggests other possibilities for their use in magnonic and spintronic devices. In this work, we use numerical methods to study the effect of geometry and external magnetic field manipulations on the localization and dynamics of SWs in crescent-shaped (CS) waveguides. It is shown that changing the magnetic field direction in these waveguides breaks the symmetry and affects the localization of eigenmodes with respect to the static demagnetizing field. This, in turn, has a direct effect on their frequency. Furthermore, CS structures are found to be characterized by significant saturation at certain field orientations, resulting in a cylindrical magnetization distribution. Thus, we present chirality-based nonreciprocal dispersion relations for high-frequency SWs, which can be controlled by the field direction (shape symmetry) and its amplitude (saturation).}, keywords = {}, pubstate = {published}, tppubtype = {article} } The research on the properties of spin waves (SWs) in three-dimensional nanosystems is an innovative idea in the field of magnonics. Mastering and understanding the nature of magnetization dynamics and binding of SWs at surfaces, edges, and in-volume parts of three-dimensional magnetic systems enables the discovery of alternative phenomena and suggests other possibilities for their use in magnonic and spintronic devices. In this work, we use numerical methods to study the effect of geometry and external magnetic field manipulations on the localization and dynamics of SWs in crescent-shaped (CS) waveguides. It is shown that changing the magnetic field direction in these waveguides breaks the symmetry and affects the localization of eigenmodes with respect to the static demagnetizing field. This, in turn, has a direct effect on their frequency. Furthermore, CS structures are found to be characterized by significant saturation at certain field orientations, resulting in a cylindrical magnetization distribution. Thus, we present chirality-based nonreciprocal dispersion relations for high-frequency SWs, which can be controlled by the field direction (shape symmetry) and its amplitude (saturation). |
174. | Bivas Rana, YoshiChika Otani Anisotropy of magnetic damping in Ta/CoFeB/MgO heterostructures Scientific Reports, 13 (1), pp. 8532, 2023, ISSN: 2045-2322. @article{rana_anisotropy_2023, title = {Anisotropy of magnetic damping in Ta/CoFeB/MgO heterostructures}, author = {Bivas Rana and YoshiChika Otani}, url = {https://www.nature.com/articles/s41598-023-35739-8}, doi = {10.1038/s41598-023-35739-8}, issn = {2045-2322}, year = {2023}, date = {2023-05-26}, urldate = {2023-05-28}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {8532}, abstract = {Magnetic damping controls the performance and operational speed of many spintronics devices. Being a tensor quantity, the damping in magnetic thin films often shows anisotropic behavior with the magnetization orientation. Here, we have studied the anisotropy of damping in Ta/CoFeB/MgO heterostructures, deposited on thermally oxidized Si substrates, as a function of the orientation of magnetization. By performing ferromagnetic resonance (FMR) measurements based on spin pumping and inverse spin Hall effect (ISHE), we extract the damping parameter in those films and find that the anisotropy of damping contains four-fold and two-fold anisotropy terms. We infer that four-fold anisotropy originates from two-magnon scattering (TMS). By studying reference Ta/CoFeB/MgO films, deposited on LiNbO3 substrates, we find that the two-fold anisotropy is correlated with in-plane magnetic anisotropy (IMA) of the films, suggesting its origin as the anisotropy in bulk spin–orbit coupling (SOC) of CoFeB film. We conclude that when IMA is very small, it’s correlation with two-fold anisotropy cannot be experimentally identified. However, as IMA increases, it starts to show a correlation with two-fold anisotropy in damping. These results will be beneficial for designing future spintronics devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Magnetic damping controls the performance and operational speed of many spintronics devices. Being a tensor quantity, the damping in magnetic thin films often shows anisotropic behavior with the magnetization orientation. Here, we have studied the anisotropy of damping in Ta/CoFeB/MgO heterostructures, deposited on thermally oxidized Si substrates, as a function of the orientation of magnetization. By performing ferromagnetic resonance (FMR) measurements based on spin pumping and inverse spin Hall effect (ISHE), we extract the damping parameter in those films and find that the anisotropy of damping contains four-fold and two-fold anisotropy terms. We infer that four-fold anisotropy originates from two-magnon scattering (TMS). By studying reference Ta/CoFeB/MgO films, deposited on LiNbO3 substrates, we find that the two-fold anisotropy is correlated with in-plane magnetic anisotropy (IMA) of the films, suggesting its origin as the anisotropy in bulk spin–orbit coupling (SOC) of CoFeB film. We conclude that when IMA is very small, it’s correlation with two-fold anisotropy cannot be experimentally identified. However, as IMA increases, it starts to show a correlation with two-fold anisotropy in damping. These results will be beneficial for designing future spintronics devices. |
173. | Shilan Abo, Jan Soubusta, Kateřina Jiráková, Karol Bartkiewicz, Antonín Černoch, Karel Lemr, Adam Miranowicz Experimental hierarchy of two-qubit quantum correlations without state tomography Scientific Reports, 13 (1), pp. 8564, 2023, ISSN: 2045-2322. @article{abo_experimental_2023, title = {Experimental hierarchy of two-qubit quantum correlations without state tomography}, author = {Shilan Abo and Jan Soubusta and Kateřina Jiráková and Karol Bartkiewicz and Antonín Černoch and Karel Lemr and Adam Miranowicz}, url = {https://www.nature.com/articles/s41598-023-35015-9}, doi = {10.1038/s41598-023-35015-9}, issn = {2045-2322}, year = {2023}, date = {2023-05-26}, urldate = {2023-10-18}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {8564}, abstract = {A Werner state, which is the singlet Bell state affected by white noise, is a prototype example of states, which can reveal a hierarchy of quantum entanglement, steering, and Bell nonlocality by controlling the amount of noise. However, experimental demonstrations of this hierarchy in a sufficient and necessary way (i.e., by applying measures or universal witnesses of these quantum correlations) have been mainly based on full quantum state tomography, corresponding to measuring at least 15 real parameters of two-qubit states. Here we report an experimental demonstration of this hierarchy by measuring only six elements of a correlation matrix depending on linear combinations of two-qubit Stokes parameters. We show that our experimental setup can also reveal the hierarchy of these quantum correlations of generalized Werner states, which are any two-qubit pure states affected by white noise.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A Werner state, which is the singlet Bell state affected by white noise, is a prototype example of states, which can reveal a hierarchy of quantum entanglement, steering, and Bell nonlocality by controlling the amount of noise. However, experimental demonstrations of this hierarchy in a sufficient and necessary way (i.e., by applying measures or universal witnesses of these quantum correlations) have been mainly based on full quantum state tomography, corresponding to measuring at least 15 real parameters of two-qubit states. Here we report an experimental demonstration of this hierarchy by measuring only six elements of a correlation matrix depending on linear combinations of two-qubit Stokes parameters. We show that our experimental setup can also reveal the hierarchy of these quantum correlations of generalized Werner states, which are any two-qubit pure states affected by white noise. |
172. | Dariia Popadiuk, Elena V. Tartakovskaya, Maciej Krawczyk, Kostyantyn Guslienko Emergent Magnetic Field and Nonzero Gyrovector of the Toroidal Magnetic Hopfion physica status solidi (RRL) – Rapid Research Letters, n/a (n/a), pp. 2300131, 2023. @article{https://doi.org/10.1002/pssr.202300131, title = {Emergent Magnetic Field and Nonzero Gyrovector of the Toroidal Magnetic Hopfion}, author = {Dariia Popadiuk and Elena V. Tartakovskaya and Maciej Krawczyk and Kostyantyn Guslienko}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pssr.202300131}, doi = {https://doi.org/10.1002/pssr.202300131}, year = {2023}, date = {2023-05-13}, journal = {physica status solidi (RRL) – Rapid Research Letters}, volume = {n/a}, number = {n/a}, pages = {2300131}, abstract = {Magnetic hopfions are localized magnetic solitons with a nonzero 3D topological charge (Hopf index). Herein, an analytical calculation of the magnetic hopfion gyrovector is presented and it is shown that it does not vanish even in an infinite sample. The calculation method is based on the concept of the emergent magnetic field. The particular case of the simplest nontrivial toroidal hopfion with the Hopf index | QH |=1$łeft|right. Q_textĦ łeft|right. = 1$ in the cylindrical magnetic dot is considered and dependencies of the gyrovector components on the dot sizes are calculated. Nonzero hopfion gyrovector is important in any description of the hopfion dynamics within the collective coordinate Thiele's approach.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Magnetic hopfions are localized magnetic solitons with a nonzero 3D topological charge (Hopf index). Herein, an analytical calculation of the magnetic hopfion gyrovector is presented and it is shown that it does not vanish even in an infinite sample. The calculation method is based on the concept of the emergent magnetic field. The particular case of the simplest nontrivial toroidal hopfion with the Hopf index | QH |=1$łeft|right. Q_textĦ łeft|right. = 1$ in the cylindrical magnetic dot is considered and dependencies of the gyrovector components on the dot sizes are calculated. Nonzero hopfion gyrovector is important in any description of the hopfion dynamics within the collective coordinate Thiele's approach. |
171. | R Mehta, Mathieu Moalic, Maciej Krawczyk, S Saha Tunability of spin-wave spectra in a 2D triangular shaped magnonic fractals Journal of Physics: Condensed Matter, 35 (32), pp. 324002, 2023. @article{Mehta_2023, title = {Tunability of spin-wave spectra in a 2D triangular shaped magnonic fractals}, author = {R Mehta and Mathieu Moalic and Maciej Krawczyk and S Saha}, url = {https://dx.doi.org/10.1088/1361-648X/acd15f}, doi = {10.1088/1361-648X/acd15f}, year = {2023}, date = {2023-05-12}, journal = {Journal of Physics: Condensed Matter}, volume = {35}, number = {32}, pages = {324002}, publisher = {IOP Publishing}, abstract = {Reprogramming the structure of the magnonic bands during their operation is important for controlling spin waves in magnonic devices. Here, we report the tunability of the spin-wave spectra for a triangular shaped deterministic magnonic fractal, which is known as Sierpinski triangle by solving the Landau–Lifshitz–Gilbert equation using a micromagnetic simulations. The spin-wave dynamics change significantly with the variation of iteration number. A wide frequency gap is observed for a structure with an iteration number exceeding some value and a plenty of mini-frequency bandgaps at structures with high iteration number. The frequency gap could be controlled by varying the strength of the magnetic field. A sixfold symmetry in the frequency gap is observed with the variation of the azimuthal angle of the external magnetic field. The spatial distributions of the spin-wave modes allow to identify the bands surrounding the gap. The observations are important for the application of magnetic fractals as a reconfigurable aperiodic magnonic crystals.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Reprogramming the structure of the magnonic bands during their operation is important for controlling spin waves in magnonic devices. Here, we report the tunability of the spin-wave spectra for a triangular shaped deterministic magnonic fractal, which is known as Sierpinski triangle by solving the Landau–Lifshitz–Gilbert equation using a micromagnetic simulations. The spin-wave dynamics change significantly with the variation of iteration number. A wide frequency gap is observed for a structure with an iteration number exceeding some value and a plenty of mini-frequency bandgaps at structures with high iteration number. The frequency gap could be controlled by varying the strength of the magnetic field. A sixfold symmetry in the frequency gap is observed with the variation of the azimuthal angle of the external magnetic field. The spatial distributions of the spin-wave modes allow to identify the bands surrounding the gap. The observations are important for the application of magnetic fractals as a reconfigurable aperiodic magnonic crystals. |
170. | J M Flores-Camacho, Bivas Rana, R E Balderas-Navarro, A Lastras-Martínez, Yoshichika Otani, Jorge Puebla Mid-infrared optical properties of non-magnetic-metal/CoFeB/MgO heterostructures Journal of Physics D: Applied Physics, 56 (31), pp. 315301, 2023. @article{Flores-Camacho_2023, title = {Mid-infrared optical properties of non-magnetic-metal/CoFeB/MgO heterostructures}, author = {J M Flores-Camacho and Bivas Rana and R E Balderas-Navarro and A Lastras-Martínez and Yoshichika Otani and Jorge Puebla}, url = {https://dx.doi.org/10.1088/1361-6463/acd00f}, doi = {10.1088/1361-6463/acd00f}, year = {2023}, date = {2023-05-09}, journal = {Journal of Physics D: Applied Physics}, volume = {56}, number = {31}, pages = {315301}, publisher = {IOP Publishing}, abstract = {We report on the optical characterization of non-magnetic metal (NM)/ferromagnetic (Co20Fe60B20)/MgO heterostructures and interfaces by using mid infrared (MIR) spectroscopic ellipsometry at room temperature. We extracted for the MIR range the dielectric function (DF) of Co20Fe60B20, that is lacking in literature, from a multisample analysis. From the optical modeling of the heterostructures we detected and determined the dielectric tensor properties of a two-dimensional electron gas (2DEG) forming at the NM and the CoFeB interface. These properties comprise independent Drude parameters for the in-plane and out-of plane tensor components, with the latter having an epsilon-near-zero frequency within our working spectral range. A feature assigned to spin–orbit coupling (SOC) is identified. Furthermore, it is found that both, the interfacial properties, 2DEG Drude parameters and SOC strength, and the apparent DF of the MgO layer depend on the type of the underlying NM, namely, Pt, W, or Cu. The results reported here should be useful in tailoring novel phenomena in such types of heterostructures by assessing their optical response noninvasively, complementing existing characterization tools such as angle-resolved photoemission spectroscopy, and those related to electron/spin transport.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report on the optical characterization of non-magnetic metal (NM)/ferromagnetic (Co20Fe60B20)/MgO heterostructures and interfaces by using mid infrared (MIR) spectroscopic ellipsometry at room temperature. We extracted for the MIR range the dielectric function (DF) of Co20Fe60B20, that is lacking in literature, from a multisample analysis. From the optical modeling of the heterostructures we detected and determined the dielectric tensor properties of a two-dimensional electron gas (2DEG) forming at the NM and the CoFeB interface. These properties comprise independent Drude parameters for the in-plane and out-of plane tensor components, with the latter having an epsilon-near-zero frequency within our working spectral range. A feature assigned to spin–orbit coupling (SOC) is identified. Furthermore, it is found that both, the interfacial properties, 2DEG Drude parameters and SOC strength, and the apparent DF of the MgO layer depend on the type of the underlying NM, namely, Pt, W, or Cu. The results reported here should be useful in tailoring novel phenomena in such types of heterostructures by assessing their optical response noninvasively, complementing existing characterization tools such as angle-resolved photoemission spectroscopy, and those related to electron/spin transport. |
169. | Andriy E. Serebryannikov, Diana C Skigin, Hodjat Hajian, Ekmel Ozbay J. Opt. Soc. Am. B, 40 (5), pp. 1340–1349, 2023. @article{Serebryannikov:23, title = {Wide-angle and simultaneously wideband blazing (deflection) enabling multifunctionality in metagratings comprising epsilon-near-zero materials}, author = {Andriy E. Serebryannikov and Diana C Skigin and Hodjat Hajian and Ekmel Ozbay}, url = {https://opg.optica.org/josab/abstract.cfm?URI=josab-40-5-1340}, doi = {10.1364/JOSAB.485457}, year = {2023}, date = {2023-05-01}, journal = {J. Opt. Soc. Am. B}, volume = {40}, number = {5}, pages = {1340--1349}, publisher = {Optica Publishing Group}, abstract = {This paper investigates diffractions by gratings made of a dispersive material in an epsilon-near-zero (ENZ) regime and having one-side corrugations, and those by two-component dielectric-ENZ gratings with the inner corrugations and flat outer interfaces. The goal is to achieve wideband and simultaneously wide-angle textminus1st order blazing (deflection) that may enable wideband spatial filtering and demultiplexing in reflection mode. Several typical scenarios are discussed, which differ in the maximum magnitude of the blazed wave and size of the blazing area observed on the frequency-incidence angle plane, as well as the contribution of the ranges of positive and negative permittivity in the vicinity of zero. The high capability of ENZ and dielectric-ENZ gratings in asymmetric reflection is demonstrated for three different levels of losses for the dispersive material.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper investigates diffractions by gratings made of a dispersive material in an epsilon-near-zero (ENZ) regime and having one-side corrugations, and those by two-component dielectric-ENZ gratings with the inner corrugations and flat outer interfaces. The goal is to achieve wideband and simultaneously wide-angle textminus1st order blazing (deflection) that may enable wideband spatial filtering and demultiplexing in reflection mode. Several typical scenarios are discussed, which differ in the maximum magnitude of the blazed wave and size of the blazing area observed on the frequency-incidence angle plane, as well as the contribution of the ranges of positive and negative permittivity in the vicinity of zero. The high capability of ENZ and dielectric-ENZ gratings in asymmetric reflection is demonstrated for three different levels of losses for the dispersive material. |
168. | Arezoo Etesamirad, Yulia Kharlan, Rodolfo Rodriguez, Igor Barsukov, Roman Verba Controlling Selection Rules for Magnon Scattering in Nanomagnets by Spatial Symmetry Breaking Phys. Rev. Appl., 19 , pp. 044087, 2023. @article{PhysRevApplied.19.044087, title = {Controlling Selection Rules for Magnon Scattering in Nanomagnets by Spatial Symmetry Breaking}, author = {Arezoo Etesamirad and Yulia Kharlan and Rodolfo Rodriguez and Igor Barsukov and Roman Verba}, url = {https://link.aps.org/doi/10.1103/PhysRevApplied.19.044087}, doi = {10.1103/PhysRevApplied.19.044087}, year = {2023}, date = {2023-04-27}, journal = {Phys. Rev. Appl.}, volume = {19}, pages = {044087}, publisher = {American Physical Society}, abstract = {Nanomagnets are the building blocks of many existing and emergent spintronic technologies. The magnetization dynamics of nanomagnets is often dominated by nonlinear processes, which have been recently shown to have many surprising features and far-reaching implications for applications. Here we develop a theoretical framework uncovering the selection rules for multimagnon processes and discuss their underlying mechanisms. For its technological relevance, we focus on the degenerate three-magnon process in thin elliptical nanodisks to illustrate our findings. We parameterize the selection rules through a set of magnon interaction coefficients which we calculate using micromagnetic simulations. We postulate the selection rules and investigate how they are altered by perturbations that break the symmetry of static magnetization configuration and spatial spin-wave profiles and that can be realized by applying off-symmetry-axis or nonuniform magnetic fields. Our work provides the phenomenological understanding of the mechanics of magnon interaction as well as the formalism for determining the interaction coefficients from simulations and experimental data. Our results serve as a guide to analyze the magnon processes inherently present in spin-torque devices in order to boost their performance or to engineer a specific nonlinear response in a nanomagnet used in a neuromorphic or quantum magnonic application.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nanomagnets are the building blocks of many existing and emergent spintronic technologies. The magnetization dynamics of nanomagnets is often dominated by nonlinear processes, which have been recently shown to have many surprising features and far-reaching implications for applications. Here we develop a theoretical framework uncovering the selection rules for multimagnon processes and discuss their underlying mechanisms. For its technological relevance, we focus on the degenerate three-magnon process in thin elliptical nanodisks to illustrate our findings. We parameterize the selection rules through a set of magnon interaction coefficients which we calculate using micromagnetic simulations. We postulate the selection rules and investigate how they are altered by perturbations that break the symmetry of static magnetization configuration and spatial spin-wave profiles and that can be realized by applying off-symmetry-axis or nonuniform magnetic fields. Our work provides the phenomenological understanding of the mechanics of magnon interaction as well as the formalism for determining the interaction coefficients from simulations and experimental data. Our results serve as a guide to analyze the magnon processes inherently present in spin-torque devices in order to boost their performance or to engineer a specific nonlinear response in a nanomagnet used in a neuromorphic or quantum magnonic application. |
167. | Ievgen I. Arkhipov, Adam Miranowicz, Fabrizio Minganti, Şahin K. Özdemir, Franco Nori Nature Communications, 14 (2076), 2023. @article{Arkhipov2023, title = {Dynamically crossing diabolic points while encircling exceptional curves: A programmable symmetric-asymmetric multimode switch}, author = {Ievgen I. Arkhipov and Adam Miranowicz and Fabrizio Minganti and Şahin K. Özdemir and Franco Nori}, url = {https://www.nature.com/articles/s41467-023-37275-5}, doi = {doi.org/10.1038/s41467-023-37275-5}, year = {2023}, date = {2023-04-12}, journal = {Nature Communications}, volume = {14}, number = {2076}, abstract = {Nontrivial spectral properties of non-Hermitian systems can lead to intriguing effects with no counterparts in Hermitian systems. For instance, in a two-mode photonic system, by dynamically winding around an exceptional point (EP) a controlled asymmetric-symmetric mode switching can be realized. That is, the system can either end up in one of its eigenstates, regardless of the initial eigenmode, or it can switch between the two states on demand, by simply controlling the winding direction. However, for multimode systems with higher-order EPs or multiple low-order EPs, the situation can be more involved, and the ability to control asymmetric-symmetric mode switching can be impeded, due to the breakdown of adiabaticity. Here we demonstrate that this difficulty can be overcome by winding around exceptional curves by additionally crossing diabolic points. We consider a four-mode PT-symmetric bosonic system as a platform for experimental realization of such a multimode switch. Our work provides alternative routes for light manipulations in non-Hermitian photonic setups.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nontrivial spectral properties of non-Hermitian systems can lead to intriguing effects with no counterparts in Hermitian systems. For instance, in a two-mode photonic system, by dynamically winding around an exceptional point (EP) a controlled asymmetric-symmetric mode switching can be realized. That is, the system can either end up in one of its eigenstates, regardless of the initial eigenmode, or it can switch between the two states on demand, by simply controlling the winding direction. However, for multimode systems with higher-order EPs or multiple low-order EPs, the situation can be more involved, and the ability to control asymmetric-symmetric mode switching can be impeded, due to the breakdown of adiabaticity. Here we demonstrate that this difficulty can be overcome by winding around exceptional curves by additionally crossing diabolic points. We consider a four-mode PT-symmetric bosonic system as a platform for experimental realization of such a multimode switch. Our work provides alternative routes for light manipulations in non-Hermitian photonic setups. |
166. | Jan Kisielewski, Paweł Gruszecki, Maciej Krawczyk, Vitalii Zablotskii, Andrzej Maziewski Between waves and patterns: Spin wave freezing in films with Dzyaloshinskii-Moriya interaction Phys. Rev. B, 107 , pp. 134416, 2023. @article{PhysRevB.107.134416, title = {Between waves and patterns: Spin wave freezing in films with Dzyaloshinskii-Moriya interaction}, author = {Jan Kisielewski and Paweł Gruszecki and Maciej Krawczyk and Vitalii Zablotskii and Andrzej Maziewski}, url = {https://link.aps.org/doi/10.1103/PhysRevB.107.134416}, doi = {10.1103/PhysRevB.107.134416}, year = {2023}, date = {2023-04-12}, journal = {Phys. Rev. B}, volume = {107}, pages = {134416}, publisher = {American Physical Society}, abstract = {The relationship between waves and static pattern formation is an intriguing effect and remains unexplained in many areas of physics, including magnetism. We study the spin-wave-mediated spin reorientation transition (SRT) in magnetic films with uniaxial magnetic anisotropy and Dzyaloshinskii-Moriya interaction (DMI). In particular, we show that propagating spin waves can freeze in the SRT, causing periodic magnetic domains to arise, which is reminiscent of the wave amplitude distribution. This process can take place under the influence of a change in the magnetic field, but also of other parameters. Interestingly, at the SRT, DMI nonreciprocity leads to the emergence of flowing magnetization patterns, which suggests a spontaneous breaking of translational symmetry, and the formation of magnonic space-time crystals. The described phenomena are general and should take place in a large family of magnetic materials. Therefore, the results should be of great importance for the further development of spintronics and magnonics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The relationship between waves and static pattern formation is an intriguing effect and remains unexplained in many areas of physics, including magnetism. We study the spin-wave-mediated spin reorientation transition (SRT) in magnetic films with uniaxial magnetic anisotropy and Dzyaloshinskii-Moriya interaction (DMI). In particular, we show that propagating spin waves can freeze in the SRT, causing periodic magnetic domains to arise, which is reminiscent of the wave amplitude distribution. This process can take place under the influence of a change in the magnetic field, but also of other parameters. Interestingly, at the SRT, DMI nonreciprocity leads to the emergence of flowing magnetization patterns, which suggests a spontaneous breaking of translational symmetry, and the formation of magnonic space-time crystals. The described phenomena are general and should take place in a large family of magnetic materials. Therefore, the results should be of great importance for the further development of spintronics and magnonics. |
165. | Grzegorz Chimczak, Anna Kowalewska‑Kudłaszyk, Ewelina Lange, Karol Bartkiewicz, Jan Peřina Jr. The effect of thermal photons on exceptional points in coupled resonators. Scientific Reports, 13 , pp. 5859, 2023. @article{Chimczak2023, title = {The effect of thermal photons on exceptional points in coupled resonators.}, author = {Grzegorz Chimczak and Anna Kowalewska‑Kudłaszyk and Ewelina Lange and Karol Bartkiewicz and Jan Peřina Jr.}, url = {https://www.nature.com/articles/s41598-023-32864-2}, doi = {https://doi.org/10.1038/s41598-023-32864-2}, year = {2023}, date = {2023-04-11}, journal = {Scientific Reports}, volume = {13}, pages = {5859}, abstract = {We analyse two quantum systems with hidden parity-time ( PT ) symmetry: one is an optical device, whereas another is a superconducting microwave-frequency device. To investigate their symmetry, we introduce a damping frame (DF), in which loss and gain terms for a given Hamiltonian are balanced. We show that the non-Hermitian Hamiltonians of both systems can be tuned to reach an exceptional point (EP), i.e., the point in parameter space at which a transition from broken to unbroken hidden PT symmetry takes place. We calculate a degeneracy of a Liouvillian superoperator, which is called the Liouvillian exceptional point (LEP), and show that, in the optical domain, LEP is equivalent to EP obtained from the non-Hermitian Hamiltonian (HEP). We also report breaking the equivalence between LEP and HEP by a non-zero number of thermal photons for the microwave-frequency system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We analyse two quantum systems with hidden parity-time ( PT ) symmetry: one is an optical device, whereas another is a superconducting microwave-frequency device. To investigate their symmetry, we introduce a damping frame (DF), in which loss and gain terms for a given Hamiltonian are balanced. We show that the non-Hermitian Hamiltonians of both systems can be tuned to reach an exceptional point (EP), i.e., the point in parameter space at which a transition from broken to unbroken hidden PT symmetry takes place. We calculate a degeneracy of a Liouvillian superoperator, which is called the Liouvillian exceptional point (LEP), and show that, in the optical domain, LEP is equivalent to EP obtained from the non-Hermitian Hamiltonian (HEP). We also report breaking the equivalence between LEP and HEP by a non-zero number of thermal photons for the microwave-frequency system. |
164. | Jolanta Natalia Latosińska, Magdalena Latosińska, Janez Seliger, Veselko Žagar, Tomaž Apih, Paweł Grieb Molecules, 28 (8), 2023, ISSN: 1420-3049. @article{molecules28083308, title = {Elucidating the Role of Noncovalent Interactions in Favipiravir, a Drug Active against Various Human RNA Viruses; a 1H-14N NQDR/Periodic DFT/QTAIM/RDS/3D Hirshfeld Surfaces Combined Study}, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Janez Seliger and Veselko Žagar and Tomaž Apih and Paweł Grieb}, url = {https://www.mdpi.com/1420-3049/28/8/3308}, doi = {10.3390/molecules28083308}, issn = {1420-3049}, year = {2023}, date = {2023-04-07}, journal = {Molecules}, volume = {28}, number = {8}, abstract = {Favipiravir (6-fluoro-3-hydroxypyrazine-2-carboxamide, FPV), an active pharmaceutical component of the drug discovered and registered in March 2014 in Japan under the name Avigan, with an indication for pandemic influenza, has been studied. The study of this compound was prompted by the idea that effective processes of recognition and binding of FPV to the nucleic acid are affected predominantly by the propensity to form intra- and intermolecular interactions. Three nuclear quadrupole resonance experimental techniques, namely 1H-14N cross-relaxation, multiple frequency sweeps, and two-frequency irradiation, followed by solid-state computational modelling (density functional theory supplemented by the quantum theory of atoms in molecules, 3D Hirshfeld Surfaces, and reduced density gradient) approaches were applied. The complete NQR spectrum consisting of nine lines indicating the presence of three chemically inequivalent nitrogen sites in the FPV molecule was detected, and the assignment of lines to particular sites was performed. The description of the nearest vicinity of all three nitrogen atoms was used to characterize the nature of the intermolecular interactions from the perspective of the local single atoms and to draw some conclusions on the nature of the interactions required for effective recognition and binding. The propensity to form the electrostatic N−H···O, N−H···N, and C−H···O intermolecular hydrogen bonds competitive with two intramolecular hydrogen bonds, strong O−H···O and very weak N−H···N, closing the 5-member ring and stiffening the structure, as well as π···π and F···F dispersive interactions, were analysed in detail. The hypothesis regarding the similarity of the interaction pattern in the solid and the RNA template was verified. It was discovered that the -NH2 group in the crystal participates in intermolecular hydrogen bonds N–H···N and N–H···O, in the precatalytic state only in N–H···O, while in the active state in N–H···N and N–H···O hydrogen bonds, which is of importance to link FVP to the RNA template. Our study elucidates the binding modes of FVP (in crystal, precatalytic, and active forms) in detail and should guide the design of more potent analogues targeting SARS-CoV-2. Strong direct binding of FVP-RTP to both the active site and cofactor discovered by us suggests a possible alternative, allosteric mechanism of FVP action, which may explain the scattering of the results of clinical trials or the synergistic effect observed in combined treatment against SARS-CoV-2.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Favipiravir (6-fluoro-3-hydroxypyrazine-2-carboxamide, FPV), an active pharmaceutical component of the drug discovered and registered in March 2014 in Japan under the name Avigan, with an indication for pandemic influenza, has been studied. The study of this compound was prompted by the idea that effective processes of recognition and binding of FPV to the nucleic acid are affected predominantly by the propensity to form intra- and intermolecular interactions. Three nuclear quadrupole resonance experimental techniques, namely 1H-14N cross-relaxation, multiple frequency sweeps, and two-frequency irradiation, followed by solid-state computational modelling (density functional theory supplemented by the quantum theory of atoms in molecules, 3D Hirshfeld Surfaces, and reduced density gradient) approaches were applied. The complete NQR spectrum consisting of nine lines indicating the presence of three chemically inequivalent nitrogen sites in the FPV molecule was detected, and the assignment of lines to particular sites was performed. The description of the nearest vicinity of all three nitrogen atoms was used to characterize the nature of the intermolecular interactions from the perspective of the local single atoms and to draw some conclusions on the nature of the interactions required for effective recognition and binding. The propensity to form the electrostatic N−H···O, N−H···N, and C−H···O intermolecular hydrogen bonds competitive with two intramolecular hydrogen bonds, strong O−H···O and very weak N−H···N, closing the 5-member ring and stiffening the structure, as well as π···π and F···F dispersive interactions, were analysed in detail. The hypothesis regarding the similarity of the interaction pattern in the solid and the RNA template was verified. It was discovered that the -NH2 group in the crystal participates in intermolecular hydrogen bonds N–H···N and N–H···O, in the precatalytic state only in N–H···O, while in the active state in N–H···N and N–H···O hydrogen bonds, which is of importance to link FVP to the RNA template. Our study elucidates the binding modes of FVP (in crystal, precatalytic, and active forms) in detail and should guide the design of more potent analogues targeting SARS-CoV-2. Strong direct binding of FVP-RTP to both the active site and cofactor discovered by us suggests a possible alternative, allosteric mechanism of FVP action, which may explain the scattering of the results of clinical trials or the synergistic effect observed in combined treatment against SARS-CoV-2. |
163. | Ali Ebrahimian, Anna Dyrdał, Alireza Qaiumzadeh Scientific Reports, 13 , pp. 5336, 2023. @article{Ebrahimian2023, title = {Control of magnetic states and spin interactions in bilayer CrCl3 with strain and electric fields: an ab initio study}, author = {Ali Ebrahimian and Anna Dyrdał and Alireza Qaiumzadeh}, url = {https://doi.org/10.1038/s41598-023-32598-1}, doi = {10.1038/s41598-023-32598-1}, year = {2023}, date = {2023-04-01}, journal = {Scientific Reports}, volume = {13}, pages = {5336}, abstract = {Using ab initio density functional theory, we demonstrated the possibility of controlling the magnetic ground-state properties of bilayer CrCl3 by means of mechanical strains and electric fields. In principle, we investigated the influence of these two fields on parameters describing the spin Hamiltonian of the system. The obtained results show that biaxial strains change the magnetic ground state between ferromagnetic and antiferromagnetic phases. The mechanical strain also affects the direction and amplitude of the magnetic anisotropy energy (MAE). Importantly, the direction and amplitude of the Dzyaloshinskii–Moriya vectors are also highly tunable under external strain and electric fields. The competition between nearest-neighbor exchange interactions, MAE, and Dzyaloshinskii–Moriya interactions can lead to the stabilization of various exotic spin textures and novel magnetic excitations. The high tunability of magnetic properties by external fields makes bilayer CrCl3 a promising candidate for application in the emerging field of two-dimensional quantum spintronics and magnonics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Using ab initio density functional theory, we demonstrated the possibility of controlling the magnetic ground-state properties of bilayer CrCl3 by means of mechanical strains and electric fields. In principle, we investigated the influence of these two fields on parameters describing the spin Hamiltonian of the system. The obtained results show that biaxial strains change the magnetic ground state between ferromagnetic and antiferromagnetic phases. The mechanical strain also affects the direction and amplitude of the magnetic anisotropy energy (MAE). Importantly, the direction and amplitude of the Dzyaloshinskii–Moriya vectors are also highly tunable under external strain and electric fields. The competition between nearest-neighbor exchange interactions, MAE, and Dzyaloshinskii–Moriya interactions can lead to the stabilization of various exotic spin textures and novel magnetic excitations. The high tunability of magnetic properties by external fields makes bilayer CrCl3 a promising candidate for application in the emerging field of two-dimensional quantum spintronics and magnonics. |
162. | Angshuman Deka, Bivas Rana, YoshiChika Otani, Yasuhiro Fukuma Journal of Physics: Condensed Matter, 35 (21), pp. 214003, 2023. @article{Deka_2023, title = {Ferromagnetic resonance excited by interfacial microwave electric field: the role of current-induced torques}, author = {Angshuman Deka and Bivas Rana and YoshiChika Otani and Yasuhiro Fukuma}, url = {https://dx.doi.org/10.1088/1361-648X/acc377}, doi = {10.1088/1361-648X/acc377}, year = {2023}, date = {2023-03-24}, journal = {Journal of Physics: Condensed Matter}, volume = {35}, number = {21}, pages = {214003}, publisher = {IOP Publishing}, abstract = {Excitation of magnetization dynamics in magnetic materials, especially in ultrathin ferromagnetic films, is of utmost importance for developing various ultrafast spintronics devices. Recently, the excitation of magnetization dynamics, i.e. ferromagnetic resonance (FMR) via electric field-induced modulation of interfacial magnetic anisotropies, has received particular attention due to several advantages, including lower power consumption. However, several additional torques generated by unavoidable microwave current induced because of the capacitive nature of the junctions may also contribute to the excitation of FMR apart from electric field-induced torques. Here, we study the FMR signals excited by applying microwave signal across the metal-oxide junction in CoFeB/MgO heterostructures with Pt and Ta buffer layers. Analysis of the resonance line shape and angular dependent behavior of resonance amplitude revealed that apart from voltage-controlled in-plane magnetic anisotropy (VC-IMA) torque a significant contribution can also arises from spin-torques and Oersted field torques originating from the flow of microwave current through metal-oxide junction. Surprisingly, the overall contribution from spin-torques and Oersted field torques are comparable to the VC-IMA torque contribution, even for a device with negligible defects. This study will be beneficial for designing future electric field-controlled spintronics devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Excitation of magnetization dynamics in magnetic materials, especially in ultrathin ferromagnetic films, is of utmost importance for developing various ultrafast spintronics devices. Recently, the excitation of magnetization dynamics, i.e. ferromagnetic resonance (FMR) via electric field-induced modulation of interfacial magnetic anisotropies, has received particular attention due to several advantages, including lower power consumption. However, several additional torques generated by unavoidable microwave current induced because of the capacitive nature of the junctions may also contribute to the excitation of FMR apart from electric field-induced torques. Here, we study the FMR signals excited by applying microwave signal across the metal-oxide junction in CoFeB/MgO heterostructures with Pt and Ta buffer layers. Analysis of the resonance line shape and angular dependent behavior of resonance amplitude revealed that apart from voltage-controlled in-plane magnetic anisotropy (VC-IMA) torque a significant contribution can also arises from spin-torques and Oersted field torques originating from the flow of microwave current through metal-oxide junction. Surprisingly, the overall contribution from spin-torques and Oersted field torques are comparable to the VC-IMA torque contribution, even for a device with negligible defects. This study will be beneficial for designing future electric field-controlled spintronics devices. |
161. | Alberto Mercurio, Shilan Abo, Fabio Mauceri, Enrico Russo, Vincenzo Macrì, Adam Miranowicz, Salvatore Savasta, Omar Di Stefano Pure Dephasing of Light-Matter Systems in the Ultrastrong and Deep-Strong Coupling Regimes Phys. Rev. Lett., 130 , pp. 123601, 2023. @article{Mercurio2023, title = {Pure Dephasing of Light-Matter Systems in the Ultrastrong and Deep-Strong Coupling Regimes}, author = {Alberto Mercurio and Shilan Abo and Fabio Mauceri and Enrico Russo and Vincenzo Macrì and Adam Miranowicz and Salvatore Savasta and Omar Di Stefano}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.130.123601}, doi = {10.1103/PhysRevLett.130.123601}, year = {2023}, date = {2023-03-21}, journal = {Phys. Rev. Lett.}, volume = {130}, pages = {123601}, abstract = {Pure dephasing originates from the nondissipative information exchange between quantum systems and environments, and plays a key role in both spectroscopy and quantum information technology. Often pure dephasing constitutes the main mechanism of decay of quantum correlations. Here we investigate how pure dephasing of one of the components of a hybrid quantum system affects the dephasing rate of the system transitions. We find that, in turn, the interaction, in the case of a light-matter system, can significantly affect the form of the stochastic perturbation describing the dephasing of a subsystem, depending on the adopted gauge. Neglecting this issue can lead to wrong and unphysical results when the interaction becomes comparable to the bare resonance frequencies of subsystems, which correspond to the ultrastrong and deep-strong coupling regimes. We present results for two prototypical models of cavity quantun electrodynamics: the quantum Rabi and the Hopfield model.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pure dephasing originates from the nondissipative information exchange between quantum systems and environments, and plays a key role in both spectroscopy and quantum information technology. Often pure dephasing constitutes the main mechanism of decay of quantum correlations. Here we investigate how pure dephasing of one of the components of a hybrid quantum system affects the dephasing rate of the system transitions. We find that, in turn, the interaction, in the case of a light-matter system, can significantly affect the form of the stochastic perturbation describing the dephasing of a subsystem, depending on the adopted gauge. Neglecting this issue can lead to wrong and unphysical results when the interaction becomes comparable to the bare resonance frequencies of subsystems, which correspond to the ultrastrong and deep-strong coupling regimes. We present results for two prototypical models of cavity quantun electrodynamics: the quantum Rabi and the Hopfield model. |
160. | Oleksandr Pastukh, Malgorzata Kac, Svitlana Pastukh, Dominika Kuźma, Mateusz Zelent, Maciej Krawczyk, Łukasz Laskowski Magnetic Behavior of the Arrays of Iron Cylindrical Nanostructures: Atomistic Spin Model Simulations Crystals, 13 (3), 2023, ISSN: 2073-4352. @article{cryst13030537, title = {Magnetic Behavior of the Arrays of Iron Cylindrical Nanostructures: Atomistic Spin Model Simulations}, author = {Oleksandr Pastukh and Malgorzata Kac and Svitlana Pastukh and Dominika Kuźma and Mateusz Zelent and Maciej Krawczyk and Łukasz Laskowski}, url = {https://www.mdpi.com/2073-4352/13/3/537}, doi = {10.3390/cryst13030537}, issn = {2073-4352}, year = {2023}, date = {2023-03-21}, journal = {Crystals}, volume = {13}, number = {3}, abstract = {Cylindrical ferromagnetic nanowires are of particular interest in nanomaterials science due to various manufacturing methods and a wide range of applications in nanotechnology, with special attention given to those with diameters less than the single domain limit. In the current study, the simulations of magnetic properties of isolated iron nanowires with a diameter of 5 nm and various aspect ratios, as well as two types of arrays of such nanowires (with hexagonal and square arrangement), were performed using atomistic spin model. In the case of a single nanowire, change of coercive field for different applied field directions with aspect ratio was discussed. It was shown that the evolution of the magnetization reversal mechanism from coherent rotation to domain wall propagation appears with increasing length of single nanowire. For the arrays of cylindrical nanostructures, it was revealed that different number of nearest neighbors for each nanostructure in square and hexagonal arrays have an influence on their magnetostatic interactions, which are the most significant for shortest interwire distances. The corresponding spin configurations during the remagnetization process showed the appearance of intermediate magnetization states (when a part of wires is magnetized parallel and part antiparallel to the field direction), connected with Barkhausen effect, which influence the observed hysteresis curves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cylindrical ferromagnetic nanowires are of particular interest in nanomaterials science due to various manufacturing methods and a wide range of applications in nanotechnology, with special attention given to those with diameters less than the single domain limit. In the current study, the simulations of magnetic properties of isolated iron nanowires with a diameter of 5 nm and various aspect ratios, as well as two types of arrays of such nanowires (with hexagonal and square arrangement), were performed using atomistic spin model. In the case of a single nanowire, change of coercive field for different applied field directions with aspect ratio was discussed. It was shown that the evolution of the magnetization reversal mechanism from coherent rotation to domain wall propagation appears with increasing length of single nanowire. For the arrays of cylindrical nanostructures, it was revealed that different number of nearest neighbors for each nanostructure in square and hexagonal arrays have an influence on their magnetostatic interactions, which are the most significant for shortest interwire distances. The corresponding spin configurations during the remagnetization process showed the appearance of intermediate magnetization states (when a part of wires is magnetized parallel and part antiparallel to the field direction), connected with Barkhausen effect, which influence the observed hysteresis curves. |
159. | Andrzej Grudka, Marcin Karczewski, Paweł Kurzyński, Jan Wójcik, Antoni Wójcik Topological invariants in quantum walks Physical Review A, 107 , pp. 032201, 2023. @article{grudka23, title = {Topological invariants in quantum walks}, author = {Andrzej Grudka and Marcin Karczewski and Paweł Kurzyński and Jan Wójcik and Antoni Wójcik}, doi = {10.1103/PhysRevA.107.032201}, year = {2023}, date = {2023-03-01}, journal = {Physical Review A}, volume = {107}, pages = {032201}, abstract = {Discrete-time quantum walks (DTQWs) provide a convenient platform for a realization of many topological phases in noninteracting systems. They often offer more possibilities than systems with a static Hamiltonian. Nevertheless, researchers are still looking for DTQW symmetries protecting topological phases and for definitions of appropriate topological invariants. Although the majority of DTQW studies on this topic focus on the so-called split-step quantum walk, two distinct topological phases can be observed in more basic models. Here we infer topological properties of the basic DTQWs directly from the mapping of the Brillouin zone to the Bloch Hamiltonian. We show that for translation-symmetric systems they can be characterized by a homotopy relative to special points. We also propose a topological invariant corresponding to this concept. This invariant indicates the number of edge states at the interface between two distinct phases.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Discrete-time quantum walks (DTQWs) provide a convenient platform for a realization of many topological phases in noninteracting systems. They often offer more possibilities than systems with a static Hamiltonian. Nevertheless, researchers are still looking for DTQW symmetries protecting topological phases and for definitions of appropriate topological invariants. Although the majority of DTQW studies on this topic focus on the so-called split-step quantum walk, two distinct topological phases can be observed in more basic models. Here we infer topological properties of the basic DTQWs directly from the mapping of the Brillouin zone to the Bloch Hamiltonian. We show that for translation-symmetric systems they can be characterized by a homotopy relative to special points. We also propose a topological invariant corresponding to this concept. This invariant indicates the number of edge states at the interface between two distinct phases. |
158. | Flavio Capotondi, Alexander Lichtenstein, Serguei Molodtsov, Leonard Mueller, Andre Philippi-Kobs, Przemysław Piekarz, Konrad J. Kapcia, Victor Tkachenko, Beata Ziaja Phys. Rev. B, 107 , pp. 094402, 2023. @article{PhysRevB.107.094402, title = {Electronic processes occurring during ultrafast demagnetization of cobalt triggered by x-ray photons tuned to the Co $L_3$ resonance}, author = {Flavio Capotondi and Alexander Lichtenstein and Serguei Molodtsov and Leonard Mueller and Andre Philippi-Kobs and Przemysław Piekarz and Konrad J. Kapcia and Victor Tkachenko and Beata Ziaja}, url = {https://link.aps.org/doi/10.1103/PhysRevB.107.094402}, doi = {10.1103/PhysRevB.107.094402}, year = {2023}, date = {2023-03-01}, journal = {Phys. Rev. B}, volume = {107}, pages = {094402}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
157. | Kacper Wrześniewski Dynamics of Superconducting Correlations Induced by Hopping in Serial Double Quantum Dot System Acta Physica Polonica A, 143 (2), pp. 160, 2023. @article{Wrześniewski2023, title = {Dynamics of Superconducting Correlations Induced by Hopping in Serial Double Quantum Dot System}, author = {Kacper Wrześniewski}, url = {http://przyrbwn.icm.edu.pl/APP/apphome.html}, doi = {10.12693/APhysPolA.143.160}, year = {2023}, date = {2023-02-27}, journal = {Acta Physica Polonica A}, volume = {143}, number = {2}, pages = {160}, abstract = {We study the quench dynamics of superconducting pairing correlations in the double quantum dotsystem coupled to superconducting and normal metallic electrodes. The quantum dots are initiallyisolated from each other, and the subsequent dynamics are induced by the sudden switching on hoppingbetween them. We focus on the time-dependence of the real and imaginary parts of dots pairing potentialand the role of the hopping amplitude and on-site Coulomb correlations. For relatively small hoppingvalues, the evolution of the pairing potential is suppressed due to a strong single-occupation blockade.As the hopping amplitude increases, the pairing potential is dynamically redistributed between thedots and can eventually assume values of opposite signs. This effect is enhanced by the presence ofstrong on-site Coulomb interactions. The discussed numerical results are obtained by means of thetime-dependent numerical renormalization group approach.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We study the quench dynamics of superconducting pairing correlations in the double quantum dotsystem coupled to superconducting and normal metallic electrodes. The quantum dots are initiallyisolated from each other, and the subsequent dynamics are induced by the sudden switching on hoppingbetween them. We focus on the time-dependence of the real and imaginary parts of dots pairing potentialand the role of the hopping amplitude and on-site Coulomb correlations. For relatively small hoppingvalues, the evolution of the pairing potential is suppressed due to a strong single-occupation blockade.As the hopping amplitude increases, the pairing potential is dynamically redistributed between thedots and can eventually assume values of opposite signs. This effect is enhanced by the presence ofstrong on-site Coulomb interactions. The discussed numerical results are obtained by means of thetime-dependent numerical renormalization group approach. |
156. | Krzysztof Paweł Wójcik, Piotr Majek Majorana Coupling and Kondo Screening of Localized Spins Acta Physica Polonica A, 143 (2), pp. 207, 2023. @article{Wójcik2023, title = {Majorana Coupling and Kondo Screening of Localized Spins}, author = {Krzysztof Paweł Wójcik and Piotr Majek}, url = {http://przyrbwn.icm.edu.pl/APP/PDF/143/app143z2p15.pdf}, doi = {10.12693/APhysPolA.143.207}, year = {2023}, date = {2023-02-27}, journal = {Acta Physica Polonica A}, volume = {143}, number = {2}, pages = {207}, abstract = {We perform a theoretical analysis of the fate of the local magnetic moment of a quantum dot coupled to a normal metallic lead and a topological superconducting wire hosting Majorana modes at the ends. By means of simple analytical tools and numerical renormalization group calculations, we show that the proximity of the Majorana mode reduces the magnetic moment from 1/4, characteristic of a free spin 1/2, to 1/16. Coupling to the normal lead then causes the Kondo effect, such that the magnetic moment is fully screened below the Kondo temperature. The latter is vastly increased for strong coupling to Majorana mode.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We perform a theoretical analysis of the fate of the local magnetic moment of a quantum dot coupled to a normal metallic lead and a topological superconducting wire hosting Majorana modes at the ends. By means of simple analytical tools and numerical renormalization group calculations, we show that the proximity of the Majorana mode reduces the magnetic moment from 1/4, characteristic of a free spin 1/2, to 1/16. Coupling to the normal lead then causes the Kondo effect, such that the magnetic moment is fully screened below the Kondo temperature. The latter is vastly increased for strong coupling to Majorana mode. |
155. | Agata Krzywicka, Tomasz P Polak Pairing Mechanism at Finite Temperatures in Bosonic Systems Acta Physica Polonica A, 143 , pp. 157, 2023. @article{Krzywicka2023, title = { Pairing Mechanism at Finite Temperatures in Bosonic Systems }, author = {Agata Krzywicka and Tomasz P Polak}, doi = {10.12693/APhysPolA.143.157}, year = {2023}, date = {2023-02-15}, journal = {Acta Physica Polonica A}, volume = {143}, pages = {157}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
154. | J Feilhauer, Mateusz Zelent, Zhiwang Zhang, J Christensen, M Mruczkiewicz Unidirectional spin-wave edge modes in magnonic crystal APL Materials, 11 (2), pp. 021104, 2023. @article{doi:10.1063/5.0134099, title = {Unidirectional spin-wave edge modes in magnonic crystal}, author = {J Feilhauer and Mateusz Zelent and Zhiwang Zhang and J Christensen and M Mruczkiewicz}, url = {https://doi.org/10.1063/5.0134099}, doi = {10.1063/5.0134099}, year = {2023}, date = {2023-02-13}, journal = {APL Materials}, volume = {11}, number = {2}, pages = {021104}, abstract = {We present a numerical demonstration of magnonic crystals hosting unidirectional, topologically protected edge states. The magnonic crystal is formed of dipolarly coupled Permalloy triangles. We show that due to the geometry of the block, the size of the structure can be scaled up. In addition, edge states can be found over a wide frequency range. Experimental detection of edge excitations in the considered system can be done with state-of-the-art techniques. Thus, we demonstrate a proof-of-concept magnonic Chern topological insulator nanostructure with simple geometry feasible for experimental realization. Furthermore, by tuning the strength of the perpendicular magnetic field, we induce a topological phase transition, which results in the change of direction of the topological edge state. Then, we demonstrate the magnonic switch based on this effect.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a numerical demonstration of magnonic crystals hosting unidirectional, topologically protected edge states. The magnonic crystal is formed of dipolarly coupled Permalloy triangles. We show that due to the geometry of the block, the size of the structure can be scaled up. In addition, edge states can be found over a wide frequency range. Experimental detection of edge excitations in the considered system can be done with state-of-the-art techniques. Thus, we demonstrate a proof-of-concept magnonic Chern topological insulator nanostructure with simple geometry feasible for experimental realization. Furthermore, by tuning the strength of the perpendicular magnetic field, we induce a topological phase transition, which results in the change of direction of the topological edge state. Then, we demonstrate the magnonic switch based on this effect. |
153. | Kuan-Yi Lee, Jhen-Dong Lin, Adam Miranowicz, Franco Nori, Huan-Yu Ku, Yueh-Nan Chen Steering-enhanced quantum metrology using superpositions of noisy phase shifts Phys. Rev. Res., 5 , pp. 013103, 2023. @article{23prr-lee, title = {Steering-enhanced quantum metrology using superpositions of noisy phase shifts}, author = {Kuan-Yi Lee and Jhen-Dong Lin and Adam Miranowicz and Franco Nori and Huan-Yu Ku and Yueh-Nan Chen}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.5.013103}, doi = {10.1103/PhysRevResearch.5.013103}, year = {2023}, date = {2023-02-13}, journal = {Phys. Rev. Res.}, volume = {5}, pages = {013103}, publisher = {American Physical Society}, abstract = {Quantum steering is an important correlation in quantum information theory. A recent work [Nat. Commun. 12, 2410 (2021)] showed that quantum steering is also useful for quantum metrology. Here, we extend the exploration of steering-enhanced quantum metrology from single noiseless phase shifts to superpositions of noisy phase shifts. As concrete examples, we consider a control system that manipulates a target system to pass through a superposition of either dephased or depolarized phase shifts channels. We show that using such superpositions of noisy phase shifts can suppress the effects of noise and improve metrology. Furthermore, we also implemented proof-of-principle experiments for a superposition of dephased phase shifts on the IBM quantum experience, demonstrating a clear improvement on metrology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Quantum steering is an important correlation in quantum information theory. A recent work [Nat. Commun. 12, 2410 (2021)] showed that quantum steering is also useful for quantum metrology. Here, we extend the exploration of steering-enhanced quantum metrology from single noiseless phase shifts to superpositions of noisy phase shifts. As concrete examples, we consider a control system that manipulates a target system to pass through a superposition of either dephased or depolarized phase shifts channels. We show that using such superpositions of noisy phase shifts can suppress the effects of noise and improve metrology. Furthermore, we also implemented proof-of-principle experiments for a superposition of dephased phase shifts on the IBM quantum experience, demonstrating a clear improvement on metrology. |
152. | Liubov Ivzhenko, Aleksey Girich, Artem Hrinchenko, Oleh Yermakov 2022 IEEE 2nd Ukrainian Microwave Week (UkrMW), pp. 214-217, 2023. @inproceedings{10037146, title = {Mechanically Tunable Topological Transition and High-Directional Propagation of Surface Waves at Bilayer Hyperbolic Metasurfaces}, author = {Liubov Ivzhenko and Aleksey Girich and Artem Hrinchenko and Oleh Yermakov}, doi = {10.1109/UkrMW58013.2022.10037146}, year = {2023}, date = {2023-02-13}, booktitle = {2022 IEEE 2nd Ukrainian Microwave Week (UkrMW)}, pages = {214-217}, abstract = {We propose simple and efficient way to control the propagation regime and direction of spoof surface plasmon-polaritons localized at bilayer hyperbolic metasurfaces. We demonstrate the photonic topological transition at the same frequency implemented with a mutual rotation of the metasurface layers. Finally, we show the tunable multidirectional in-plane canalization of surface waves adjusting by the interlayer coupling. These results discover new opportunities for the manipulation over surface waves at metasurfaces.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } We propose simple and efficient way to control the propagation regime and direction of spoof surface plasmon-polaritons localized at bilayer hyperbolic metasurfaces. We demonstrate the photonic topological transition at the same frequency implemented with a mutual rotation of the metasurface layers. Finally, we show the tunable multidirectional in-plane canalization of surface waves adjusting by the interlayer coupling. These results discover new opportunities for the manipulation over surface waves at metasurfaces. |
151. | Sergey Polevoy, Ganna Kharchenko, Tetiana Kalmykova, Yevhenii Ostryzhnyi, Liubov Ivzhenko, Oleh Yermakov Polarization-Controlled Excitation of Surface Waves at Self-Complementary Metasurface 2022 IEEE 2nd Ukrainian Microwave Week (UkrMW), pp. 222-225, 2023. @inproceedings{10036966, title = {Polarization-Controlled Excitation of Surface Waves at Self-Complementary Metasurface}, author = {Sergey Polevoy and Ganna Kharchenko and Tetiana Kalmykova and Yevhenii Ostryzhnyi and Liubov Ivzhenko and Oleh Yermakov}, doi = {10.1109/UkrMW58013.2022.10036966}, year = {2023}, date = {2023-02-13}, booktitle = {2022 IEEE 2nd Ukrainian Microwave Week (UkrMW)}, pages = {222-225}, abstract = {In this work, we study the surface electromagnetic waves propagating along the self-complementary metasurface. We propose a way to excite the surface waves of the necessary polarization by using the TE-TM degeneracy property of the self-complementary metasurface. In particular, we demonstrate the excitation of surface waves with linear horizontal, vertical and diagonal as well as circular polarizations. The proposed technique opens new possibilities for the in-plane signal transferring and transformation.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } In this work, we study the surface electromagnetic waves propagating along the self-complementary metasurface. We propose a way to excite the surface waves of the necessary polarization by using the TE-TM degeneracy property of the self-complementary metasurface. In particular, we demonstrate the excitation of surface waves with linear horizontal, vertical and diagonal as well as circular polarizations. The proposed technique opens new possibilities for the in-plane signal transferring and transformation. |
150. | Anand Manaparambil, Ireneusz Weymann Nonequilibrium Seebeck effect and thermoelectric efficiency of Kondo-correlated molecular junctions Phys. Rev. B, 107 , pp. 085404, 2023. @article{Manaparambil2023, title = {Nonequilibrium Seebeck effect and thermoelectric efficiency of Kondo-correlated molecular junctions}, author = {Anand Manaparambil and Ireneusz Weymann}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.107.085404}, doi = {10.1103/PhysRevB.107.085404}, year = {2023}, date = {2023-02-07}, journal = {Phys. Rev. B}, volume = {107}, pages = {085404}, abstract = {We theoretically study the nonequilibrium thermoelectric transport properties of a strongly-correlated molecule (or quantum dot) embedded in a tunnel junction. Assuming that the coupling of the molecule to the contacts is asymmetric, we determine the nonlinear current driven by the voltage and temperature gradients by using the perturbation theory. However, the subsystem consisting of the molecule strongly coupled to one of the contacts is solved by using the numerical renormalization group method, which allows for accurate description of Kondo correlations. We study the temperature gradient and voltage dependence of the nonlinear and differential Seebeck coefficients for various initial configurations of the system. In particular, we show that in the Coulomb blockade regime with singly occupied molecule, both thermopowers exhibit sign changes due to the Kondo correlations at nonequilibrium conditions. Moreover, we determine the nonlinear heat current and thermoelectric efficiency, demonstrating that the system can work as a heat engine with considerable efficiency, depending on the transport regime.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We theoretically study the nonequilibrium thermoelectric transport properties of a strongly-correlated molecule (or quantum dot) embedded in a tunnel junction. Assuming that the coupling of the molecule to the contacts is asymmetric, we determine the nonlinear current driven by the voltage and temperature gradients by using the perturbation theory. However, the subsystem consisting of the molecule strongly coupled to one of the contacts is solved by using the numerical renormalization group method, which allows for accurate description of Kondo correlations. We study the temperature gradient and voltage dependence of the nonlinear and differential Seebeck coefficients for various initial configurations of the system. In particular, we show that in the Coulomb blockade regime with singly occupied molecule, both thermopowers exhibit sign changes due to the Kondo correlations at nonequilibrium conditions. Moreover, we determine the nonlinear heat current and thermoelectric efficiency, demonstrating that the system can work as a heat engine with considerable efficiency, depending on the transport regime. |
149. | Marceli Koralewski, Małgorzata Paprzycka Journal of Molecular Liquids, 375 , pp. 121375, 2023. @article{Koralewski2023, title = {Faraday effect and refractive index of some imidazolium-based room-temperature ionic liquids and magnetic ionic liquids}, author = {Marceli Koralewski and Małgorzata Paprzycka}, doi = {10.1016/j.molliq.2023.121375}, year = {2023}, date = {2023-02-02}, journal = {Journal of Molecular Liquids}, volume = {375}, pages = {121375}, abstract = {Knowledge of the Faraday effect (FE) is very important in fundamental research and applications. Here, we report FE and refractive index studies for two magnetic ionic liquids (MILs), namely 1-ethyl- and 1-butyl-3-methylimidazolium tetrachloroferrate. Similar studies are also conducted for ionic liquids (ILs) that have a diamagnetic counteranion in place of [FeCl4]. The magnitudes of the Verdet constants of MILs are comparable and exhibit a negative sign. Furthermore, they are about one order larger than those of ILs with a diamagnetic counteranion of a positive sign. The Verdet constant shows monotonic variations as a function of wavelength in the range from 450 to 650 nm and is mainly related to charge transfer transitions in [FeCl4], with bands located in the UV region, though the contribution of d-d transitions in Fe+3 is negligible. A model for describing the measured Verdet constant data as a function of wavelength and temperature is given with respective values of effective Faraday A-, B-, and D-terms. The introduction of an empirical rule allows the estimation of Verdet constants of iron and imidazolium derivative based MILs, which are in some cases very high, thus indicating their potential in photonics applications. Imidazole shows a positive and nearly-two orders lower magnitude of the Verdet constant. The mixture of an MIL and acetonitrile allows the tuning of both the Verdet constant and the refractive index. The refractive indices, thermo-optic coefficients, and electronic polarizabilities of MILs are higher than those of ILs with a diamagnetic counteranion.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Knowledge of the Faraday effect (FE) is very important in fundamental research and applications. Here, we report FE and refractive index studies for two magnetic ionic liquids (MILs), namely 1-ethyl- and 1-butyl-3-methylimidazolium tetrachloroferrate. Similar studies are also conducted for ionic liquids (ILs) that have a diamagnetic counteranion in place of [FeCl4]. The magnitudes of the Verdet constants of MILs are comparable and exhibit a negative sign. Furthermore, they are about one order larger than those of ILs with a diamagnetic counteranion of a positive sign. The Verdet constant shows monotonic variations as a function of wavelength in the range from 450 to 650 nm and is mainly related to charge transfer transitions in [FeCl4], with bands located in the UV region, though the contribution of d-d transitions in Fe+3 is negligible. A model for describing the measured Verdet constant data as a function of wavelength and temperature is given with respective values of effective Faraday A-, B-, and D-terms. The introduction of an empirical rule allows the estimation of Verdet constants of iron and imidazolium derivative based MILs, which are in some cases very high, thus indicating their potential in photonics applications. Imidazole shows a positive and nearly-two orders lower magnitude of the Verdet constant. The mixture of an MIL and acetonitrile allows the tuning of both the Verdet constant and the refractive index. The refractive indices, thermo-optic coefficients, and electronic polarizabilities of MILs are higher than those of ILs with a diamagnetic counteranion. |
148. | Jolanta Natalia Latosińska, Magdalena Latosińska, Andrzei Orzeszko, Jan Krzysztof Maurin Molecules, 28 (1), pp. 147, 2023. @article{Latosińska2023, title = {Synthesis and Crystal Structure of Adamantylated 4,5,6,7-tetrahalogeno-1H-benzimidazoles Novel Multi-Target Ligands (Potential CK2, M2 and SARS-CoV-2 Inhibitors). X-ray/DFT/QTAIM/Hirshfeld Surfaces/Molecular Docking Study }, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Andrzei Orzeszko and Jan Krzysztof Maurin }, doi = {10.3390/molecules28010147}, year = {2023}, date = {2023-01-02}, journal = {Molecules}, volume = {28}, number = {1}, pages = {147}, abstract = {A series of new congeners, 1-[2-(1-adamantyl)ethyl]-1H-benzimidazole (AB) and 1-[2-(1-adamantyl)ethyl]-4,5,6,7-tetrahalogeno-1H-benzimidazole (Hal=Cl, Br, I; tClAB, tBrAB, tIAB), have been synthesized and studied. These novel multi-target ligands combine a benzimidazole ring known to show antitumor activity and an adamantyl moiety showing anti-influenza activity. Their crystal structures were determined by X-ray, while intermolecular interactions were studied using topological Bader’s Quantum Theory of Atoms in Molecules, Hirshfeld Surfaces, CLP and PIXEL approaches. The newly synthesized compounds crystallize within two different space groups, P-1 (AB and tIAB) and P21/c (tClAB and tBrAB). A number of intramolecular hydrogen bonds, C−H⋯Hal (Hal=Cl, Br, I), were found in all halogen-containing congeners studied, but the intermolecular C−H⋯N hydrogen bond was detected only in AB and tIAB, while C−Hal⋯π only in tClAB and tBrAB. The interplay between C−H⋯N and C−H⋯Hal hydrogen bonds and a shift from the strong (C−H⋯Cl) to the very weak (C−H⋯I) attractive interactions upon Hal exchange, supplemented with Hal⋯Hal overlapping, determines the differences in the symmetry of crystalline packing and is crucial from the biological point of view. The hypothesis about the potential dual inhibitor role of the newly synthesized congeners was verified using molecular docking and the congeners were found to be pharmaceutically attractive as Human Casein Kinase 2, CK2, inhibitors, Membrane Matrix 2 Protein, M2, blockers and Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2, inhibitors. The addition of adamantyl moiety seems to broaden and modify the therapeutic indices of the 4,5,6,7-tetrahalogeno-1H-benzimidazoles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A series of new congeners, 1-[2-(1-adamantyl)ethyl]-1H-benzimidazole (AB) and 1-[2-(1-adamantyl)ethyl]-4,5,6,7-tetrahalogeno-1H-benzimidazole (Hal=Cl, Br, I; tClAB, tBrAB, tIAB), have been synthesized and studied. These novel multi-target ligands combine a benzimidazole ring known to show antitumor activity and an adamantyl moiety showing anti-influenza activity. Their crystal structures were determined by X-ray, while intermolecular interactions were studied using topological Bader’s Quantum Theory of Atoms in Molecules, Hirshfeld Surfaces, CLP and PIXEL approaches. The newly synthesized compounds crystallize within two different space groups, P-1 (AB and tIAB) and P21/c (tClAB and tBrAB). A number of intramolecular hydrogen bonds, C−H⋯Hal (Hal=Cl, Br, I), were found in all halogen-containing congeners studied, but the intermolecular C−H⋯N hydrogen bond was detected only in AB and tIAB, while C−Hal⋯π only in tClAB and tBrAB. The interplay between C−H⋯N and C−H⋯Hal hydrogen bonds and a shift from the strong (C−H⋯Cl) to the very weak (C−H⋯I) attractive interactions upon Hal exchange, supplemented with Hal⋯Hal overlapping, determines the differences in the symmetry of crystalline packing and is crucial from the biological point of view. The hypothesis about the potential dual inhibitor role of the newly synthesized congeners was verified using molecular docking and the congeners were found to be pharmaceutically attractive as Human Casein Kinase 2, CK2, inhibitors, Membrane Matrix 2 Protein, M2, blockers and Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2, inhibitors. The addition of adamantyl moiety seems to broaden and modify the therapeutic indices of the 4,5,6,7-tetrahalogeno-1H-benzimidazoles. |
147. | Pavlo V Bondarenko, Julia Kharlan, Sergey A Bunyaev, Olga Salyuk, Ivan R Aseguinolaza, Jose M Barandiaran, Gleb N Kakazei, Volodymyr Chernenko, Vladimir O Golub Giant four-fold magnetic anisotropy in nanotwinned NiMnGa epitaxial films APL Materials, 11 (12), pp. 121114, 2023, ISSN: 2166-532X. @article{10.1063/5.0162561b, title = {Giant four-fold magnetic anisotropy in nanotwinned NiMnGa epitaxial films}, author = {Pavlo V Bondarenko and Julia Kharlan and Sergey A Bunyaev and Olga Salyuk and Ivan R Aseguinolaza and Jose M Barandiaran and Gleb N Kakazei and Volodymyr Chernenko and Vladimir O Golub}, url = {https://doi.org/10.1063/5.0162561}, doi = {10.1063/5.0162561}, issn = {2166-532X}, year = {2023}, date = {2023-01-01}, journal = {APL Materials}, volume = {11}, number = {12}, pages = {121114}, abstract = {A giant four-fold magnetic anisotropy (with an anisotropy field up to 4 kOe) was observed in the twinned NiMnGa epitaxial film. Its appearance is explained in terms of moderate coupling between twin variants having strong uniaxial magnetocrystalline anisotropies directed orthogonally when the intertwin exchange field is comparable with the anisotropy field. This finding paves the way to increase the order of magnetic anisotropy in a many-component system while keeping the value of the anisotropy field by tuning the intercomponent exchange strength and can be extended to exchange-coupled multilayers and arrays of nanoelements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A giant four-fold magnetic anisotropy (with an anisotropy field up to 4 kOe) was observed in the twinned NiMnGa epitaxial film. Its appearance is explained in terms of moderate coupling between twin variants having strong uniaxial magnetocrystalline anisotropies directed orthogonally when the intertwin exchange field is comparable with the anisotropy field. This finding paves the way to increase the order of magnetic anisotropy in a many-component system while keeping the value of the anisotropy field by tuning the intercomponent exchange strength and can be extended to exchange-coupled multilayers and arrays of nanoelements. |
146. | Jan Wójcik, Grzegorz Chimczak Electrically coupled optomechanical cavities as a tool for quantum nondemolition measurement Physics Letters A, 490 , pp. 129187, 2023, ISSN: 0375-9601. @article{WOJCIK2023129187, title = {Electrically coupled optomechanical cavities as a tool for quantum nondemolition measurement}, author = {Jan Wójcik and Grzegorz Chimczak}, url = {https://www.sciencedirect.com/science/article/pii/S0375960123005674}, doi = {https://doi.org/10.1016/j.physleta.2023.129187}, issn = {0375-9601}, year = {2023}, date = {2023-01-01}, journal = {Physics Letters A}, volume = {490}, pages = {129187}, abstract = {We present a new model of two electrically coupled optomechanical cavities. This model is based on the recently presented proposal [Physical Review A 103 (2021) 043509]. We found that coupling two optomechanical cavities via Coulomb force leads to cross-Kerr interactions between those cavities. We show that such systems may be ideal for a protocol of quantum non-demolition measurement because it is easy to eliminate the self-phase modulation effect. Moreover, nonlinearities in our model are based on easily adjustable parameters, and therefore, given recent experimental studies, we believe that experimental realization of a cross-Kerr interaction via Coulomb force coupling is feasible.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a new model of two electrically coupled optomechanical cavities. This model is based on the recently presented proposal [Physical Review A 103 (2021) 043509]. We found that coupling two optomechanical cavities via Coulomb force leads to cross-Kerr interactions between those cavities. We show that such systems may be ideal for a protocol of quantum non-demolition measurement because it is easy to eliminate the self-phase modulation effect. Moreover, nonlinearities in our model are based on easily adjustable parameters, and therefore, given recent experimental studies, we believe that experimental realization of a cross-Kerr interaction via Coulomb force coupling is feasible. |
145. | Marceli Koralewski, Małgorzata Paprzycka, Alice Goyal, Krzysztof Gibasiewicz Faraday rotation enhancement for colloidal spherical Au and Ag nanoparticles and their mixtures Journal of Magnetism and Magnetic Materials, 588 , pp. 171461, 2023, ISSN: 0304-8853. @article{Koralewski2023b, title = {Faraday rotation enhancement for colloidal spherical Au and Ag nanoparticles and their mixtures}, author = {Marceli Koralewski and Małgorzata Paprzycka and Alice Goyal and Krzysztof Gibasiewicz}, url = {http://dx.doi.org/10.1016/j.jmmm.2023.171461}, doi = {10.1016/j.jmmm.2023.171461}, issn = {0304-8853}, year = {2023}, date = {2023-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {588}, pages = {171461}, publisher = {Elsevier BV}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
144. | Marceli Koralewski, Małgorzata Paprzycka, Katarina Siposova, Oskar Sobotka The kinetics of aggregation of the Aβ1-40 peptide monitored by magnetooptical methods Journal of Magnetism and Magnetic Materials, 587 , pp. 171273, 2023, ISSN: 0304-8853. @article{Koralewski2023c, title = {The kinetics of aggregation of the Aβ1-40 peptide monitored by magnetooptical methods}, author = {Marceli Koralewski and Małgorzata Paprzycka and Katarina Siposova and Oskar Sobotka}, url = {http://dx.doi.org/10.1016/j.jmmm.2023.171273}, doi = {10.1016/j.jmmm.2023.171273}, issn = {0304-8853}, year = {2023}, date = {2023-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {587}, pages = {171273}, publisher = {Elsevier BV}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
143. | Paweł Gruszecki, Jan Kisielewski Scientific Reports, 13 (1), pp. 1218, 2023, ISSN: 2045-2322. @article{gruszecki_influence_2023, title = {Influence of Dzyaloshinskii–Moriya interaction and perpendicular anisotropy on spin waves propagation in stripe domain patterns and spin spirals}, author = {Paweł Gruszecki and Jan Kisielewski}, url = {https://www.nature.com/articles/s41598-023-28271-2}, doi = {10.1038/s41598-023-28271-2}, issn = {2045-2322}, year = {2023}, date = {2023-01-01}, urldate = {2023-01-25}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {1218}, abstract = {Texture-based magnonics focuses on the utilization of spin waves in magnetization textures to process information. Using micromagnetic simulations, we study how (1) the dynamic magnetic susceptibility, (2) dispersion relations, and (3) the equilibrium magnetic configurations in periodic magnetization textures in a ultrathin ferromagnetic film in remanence depend on the values of the Dzyaloshinskii–Moriya interaction and the perpendicular magnetocrystalline anisotropy. We observe that for large Dzyaloshinskii–Moriya interaction values, spin spirals with periods of tens of nanometers are the preferred state; for small Dzyaloshinskii–Moriya interaction values and large anisotropies, stripe domain patterns with over a thousand times larger period are preferable. We observe and explain the selectivity of the excitation of resonant modes by a linearly polarized microwave field. We study the propagation of spin waves along and perpendicular to the direction of the periodicity. For propagation along the direction of the periodicity, we observe a bandgap that closes and reopens, which is accompanied by a swap in the order of the bands. For waves propagating in the perpendicular direction, some modes can be used for unidirectional channeling of spin waves. Overall, our findings are promising in sensing and signal processing applications and explain the fundamental properties of periodic magnetization textures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Texture-based magnonics focuses on the utilization of spin waves in magnetization textures to process information. Using micromagnetic simulations, we study how (1) the dynamic magnetic susceptibility, (2) dispersion relations, and (3) the equilibrium magnetic configurations in periodic magnetization textures in a ultrathin ferromagnetic film in remanence depend on the values of the Dzyaloshinskii–Moriya interaction and the perpendicular magnetocrystalline anisotropy. We observe that for large Dzyaloshinskii–Moriya interaction values, spin spirals with periods of tens of nanometers are the preferred state; for small Dzyaloshinskii–Moriya interaction values and large anisotropies, stripe domain patterns with over a thousand times larger period are preferable. We observe and explain the selectivity of the excitation of resonant modes by a linearly polarized microwave field. We study the propagation of spin waves along and perpendicular to the direction of the periodicity. For propagation along the direction of the periodicity, we observe a bandgap that closes and reopens, which is accompanied by a swap in the order of the bands. For waves propagating in the perpendicular direction, some modes can be used for unidirectional channeling of spin waves. Overall, our findings are promising in sensing and signal processing applications and explain the fundamental properties of periodic magnetization textures. |