List of publications
Department of Mesoscopic Physics
Department of Nonlinear Optics
Department of Physics of Nanostructures
Department of Theory of Condensed Matter
2024 |
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| 253. | Aleksey Girich, Liubov Ivzhenko, Ganna Kharchenko, Sergey Polevoy, Sergey Tarapov, Maciej Krawczyk, Jarosław W. Kłos Existence of edge modes in periodic microstrip transmission line Scientific Reports, 14 (1), pp. 16477, 2024, ISSN: 2045-2322. @article{girich_existence_2024, title = {Existence of edge modes in periodic microstrip transmission line}, author = {Aleksey Girich and Liubov Ivzhenko and Ganna Kharchenko and Sergey Polevoy and Sergey Tarapov and Maciej Krawczyk and Jarosław W. Kłos}, url = {https://www.nature.com/articles/s41598-024-67610-9}, doi = {10.1038/s41598-024-67610-9}, issn = {2045-2322}, year = {2024}, date = {2024-07-16}, urldate = {2024-07-17}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {16477}, abstract = {The microstrip of modulated width is a realization of a one-dimensional photonic crystal operating in the microwave regime. Like any photonic crystal, the periodic microstrip is characterised by the presence of frequency bands and band gaps that enable and prohibit wave propagation, respectively. The frequency bands for microstrip of the symmetric unit cell can be distinguished by 0 or pi Zak phase. The sum of these topological parameters for all bands below a given frequency gap determines the value of the surface impedance at the end of the microstrip. We demonstrate that edge modes are absent in a finite microstrip terminated at both ends in the centres of unit cells, but they can be induced by adding the defected cells. Edge modes present at both ends of the microstrip enable microwave tunneling with high transitivity in the frequency gap with or without a change in phase. This has been demonstrated experimentally and developed in detail using numerical simulations and model calculations. The investigated system, with a doublet of edge modes in the frequency gap, can be considered as a narrow passband filter of high selectivity and characterised by a significant group delay.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The microstrip of modulated width is a realization of a one-dimensional photonic crystal operating in the microwave regime. Like any photonic crystal, the periodic microstrip is characterised by the presence of frequency bands and band gaps that enable and prohibit wave propagation, respectively. The frequency bands for microstrip of the symmetric unit cell can be distinguished by 0 or pi Zak phase. The sum of these topological parameters for all bands below a given frequency gap determines the value of the surface impedance at the end of the microstrip. We demonstrate that edge modes are absent in a finite microstrip terminated at both ends in the centres of unit cells, but they can be induced by adding the defected cells. Edge modes present at both ends of the microstrip enable microwave tunneling with high transitivity in the frequency gap with or without a change in phase. This has been demonstrated experimentally and developed in detail using numerical simulations and model calculations. The investigated system, with a doublet of edge modes in the frequency gap, can be considered as a narrow passband filter of high selectivity and characterised by a significant group delay. |
| 252. | Ryszard Taranko, Kacper Wrześniewski, Ireneusz Weymann, Tadeusz Domański Transient effects in quantum dots contacted via topological superconductor Physical Review B, 110 , pp. 035413, 2024. @article{Taranko2024, title = {Transient effects in quantum dots contacted via topological superconductor}, author = {Ryszard Taranko and Kacper Wrześniewski and Ireneusz Weymann and Tadeusz Domański}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.110.035413}, doi = {10.1103/PhysRevB.110.035413}, year = {2024}, date = {2024-07-10}, journal = {Physical Review B}, volume = {110}, pages = {035413}, abstract = {We investigate gradual development of the quasiparticle states in two quantum dots attached to opposite sides of the topological superconducting nanowire, hosting the boundary modes. Specifically, we explore the nonequilibrium cross-correlations transmitted between these quantum dots via the zero-energy Majorana modes. Our analytical and numerical results reveal the nonlocal features observable in the transient behavior of electron pairing, which subsequently cease while the hybrid structure evolves towards its asymptotic steady-state configuration. We estimate duration of these temporary phenomena. Using the nonperturbative scheme of the time-dependent numerical renormalization group technique we also analyze nonequilibrium signatures of the correlation effects competing with the proximity induced electron pairing. These dynamical processes could manifest themselves in braiding protocols imposed on the topological and/or conventional superconducting quantum bits, using superconducting hybrid nanostructures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate gradual development of the quasiparticle states in two quantum dots attached to opposite sides of the topological superconducting nanowire, hosting the boundary modes. Specifically, we explore the nonequilibrium cross-correlations transmitted between these quantum dots via the zero-energy Majorana modes. Our analytical and numerical results reveal the nonlocal features observable in the transient behavior of electron pairing, which subsequently cease while the hybrid structure evolves towards its asymptotic steady-state configuration. We estimate duration of these temporary phenomena. Using the nonperturbative scheme of the time-dependent numerical renormalization group technique we also analyze nonequilibrium signatures of the correlation effects competing with the proximity induced electron pairing. These dynamical processes could manifest themselves in braiding protocols imposed on the topological and/or conventional superconducting quantum bits, using superconducting hybrid nanostructures. |
| 251. | Anna Krzyżewska, Anna Dyrdał Phys. Status Solidi RRL, 2024, ISSN: 1862-6254. @article{Krzyzewska2024Jun, title = {Nonlinear Hall Effect in Isotropic k-Cubed Rashba Model: Berry-Curvature-Dipole Engineering by In-Plane Magnetic Field}, author = {Anna Krzyżewska and Anna Dyrdał}, url = {https://onlinelibrary.wiley.com/doi/10.1002/pssr.202400123 https://arxiv.org/abs/2404.07352}, doi = {10.1002/pssr.202400123}, issn = {1862-6254}, year = {2024}, date = {2024-06-25}, journal = {Phys. Status Solidi RRL}, abstract = {The linear and nonlinear Hall effects in 2D electron gas are considered theoretically within the isotropic k-cubed Rashba model. It is shown that the presence of an out-of-plane external magnetic field or net magnetization is a necessary condition to induce a nonzero Berry curvature in the system, whereas an in-plane magnetic field tunes the Berry curvature leading to the Berry curvature dipole. Interestingly, in the linear response regime, the conductivity is dominated by the intrinsic component (Berry curvature component), whereas the second-order correction to the Hall current (i.e., the conductivity proportional to the external electric field) is dominated by the component independent of the Berry curvature dipole.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The linear and nonlinear Hall effects in 2D electron gas are considered theoretically within the isotropic k-cubed Rashba model. It is shown that the presence of an out-of-plane external magnetic field or net magnetization is a necessary condition to induce a nonzero Berry curvature in the system, whereas an in-plane magnetic field tunes the Berry curvature leading to the Berry curvature dipole. Interestingly, in the linear response regime, the conductivity is dominated by the intrinsic component (Berry curvature component), whereas the second-order correction to the Hall current (i.e., the conductivity proportional to the external electric field) is dominated by the component independent of the Berry curvature dipole. |
| 250. | Miłosz Zdunek, Shashank Shekhar, Sławomir Mielcarek, Aleksandra Trzaskowska Investigation of phonons and magnons in [Ni80Fe20/Au/Co/Au]N multilayers Journal of Physics: Condensed Matter, 36 (37), pp. 375801, 2024. @article{Zdunek_2024, title = {Investigation of phonons and magnons in [Ni80Fe20/Au/Co/Au]N multilayers}, author = {Miłosz Zdunek and Shashank Shekhar and Sławomir Mielcarek and Aleksandra Trzaskowska}, url = {https://dx.doi.org/10.1088/1361-648X/ad5486}, doi = {10.1088/1361-648X/ad5486}, year = {2024}, date = {2024-06-18}, journal = {Journal of Physics: Condensed Matter}, volume = {36}, number = {37}, pages = {375801}, publisher = {IOP Publishing}, abstract = {The interaction between phonons and magnons is a rapidly developing area of research, particularly in the field of acoustic spintronics. To discuss this interaction, it is necessary to observe two different waves (acoustic and spin waves) with the same frequency and wavelength. In the Ni80Fe20/Au/Co/Au system deposited on a silicon substrate, we observe the interaction between spin waves and surface acoustic waves using Brillouin light scattering spectroscopy. As a result, we can selectively control (activate or deactivate) the magnetoelastic interaction between the fundamental spin wave mode and surface acoustic waves. This is achieved by adjusting the magnetostrictive layer thickness in the multilayer. We demonstrate that by adjusting the number of layers in a multilayer structure, it is possible to precisely control the dispersion of surface acoustic waves while having minimal impact on the fundamental spin wave mode.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The interaction between phonons and magnons is a rapidly developing area of research, particularly in the field of acoustic spintronics. To discuss this interaction, it is necessary to observe two different waves (acoustic and spin waves) with the same frequency and wavelength. In the Ni80Fe20/Au/Co/Au system deposited on a silicon substrate, we observe the interaction between spin waves and surface acoustic waves using Brillouin light scattering spectroscopy. As a result, we can selectively control (activate or deactivate) the magnetoelastic interaction between the fundamental spin wave mode and surface acoustic waves. This is achieved by adjusting the magnetostrictive layer thickness in the multilayer. We demonstrate that by adjusting the number of layers in a multilayer structure, it is possible to precisely control the dispersion of surface acoustic waves while having minimal impact on the fundamental spin wave mode. |
| 249. | Grzegorz Górski, Krzysztof Paweł Wójcik, Jan Barański, Ireneusz Weymann, Tadeusz Domański Nonlocal correlations transmitted between quantum dots via short topological superconductor Scientific Reports, 13 , pp. 13848, 2024. @article{Górski2024, title = {Nonlocal correlations transmitted between quantum dots via short topological superconductor}, author = {Grzegorz Górski and Krzysztof Paweł Wójcik and Jan Barański and Ireneusz Weymann and Tadeusz Domański }, url = {https://www.nature.com/articles/s41598-024-64578-4}, doi = {10.1038/s41598-024-64578-4}, year = {2024}, date = {2024-06-15}, journal = {Scientific Reports}, volume = {13}, pages = {13848}, abstract = {We study the quasiparticle states and nonlocal correlations of a hybrid structure, comprising two quantum dots interconnected through a short-length topological superconducting nanowire hosting overlaping Majorana modes. We show that the hybridization between different components of this setup gives rise to the emergence of molecular states, which are responsible for nonlocal correlations. We inspect the resulting energy structure, focusing on the inter-dependence between the quasiparticles of individual quantum dots. We predict the existence of nonlocal effects, which could be accessed and probed by crossed Andreev reflection spectroscopy. Our study would be relevant to a recent experimental realization of the minimal Kitaev model [T. Dvir et al., Nature 614, 445 (2023)], by considering its hybrid structure with side-attached quantum dots.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We study the quasiparticle states and nonlocal correlations of a hybrid structure, comprising two quantum dots interconnected through a short-length topological superconducting nanowire hosting overlaping Majorana modes. We show that the hybridization between different components of this setup gives rise to the emergence of molecular states, which are responsible for nonlocal correlations. We inspect the resulting energy structure, focusing on the inter-dependence between the quasiparticles of individual quantum dots. We predict the existence of nonlocal effects, which could be accessed and probed by crossed Andreev reflection spectroscopy. Our study would be relevant to a recent experimental realization of the minimal Kitaev model [T. Dvir et al., Nature 614, 445 (2023)], by considering its hybrid structure with side-attached quantum dots. |
| 248. | Benedetta Flebus, Dirk Grundler, Bivas Rana, YoshiChika Otani, Igor Barsukov, Anjan Barman, Gianluca Gubbiotti, Pedro Landeros, Johan Akerman, Ursula Ebels, Philipp Pirro, Vladislav E Demidov, Katrin Schultheiss, Gyorgy Csaba, Qi Wang, Florin Ciubotaru, Dmitri E Nikonov, Ping Che, Riccardo Hertel, Teruo Ono, Dmytro Afanasiev, Johan Mentink, Theo Rasing, Burkard Hillebrands, Silvia Viola Kusminskiy, Wei Zhang, Chunhui Rita Du, Aurore Finco, Toeno van der Sar, Yunqiu Kelly Luo, Yoichi Shiota, Joseph Sklenar, Tao Yu, Jinwei Rao Journal of Physics: Condensed Matter, 36 (36), pp. 363501, 2024. @article{Flebus_2024, title = {The 2024 magnonics roadmap}, author = {Benedetta Flebus and Dirk Grundler and Bivas Rana and YoshiChika Otani and Igor Barsukov and Anjan Barman and Gianluca Gubbiotti and Pedro Landeros and Johan Akerman and Ursula Ebels and Philipp Pirro and Vladislav E Demidov and Katrin Schultheiss and Gyorgy Csaba and Qi Wang and Florin Ciubotaru and Dmitri E Nikonov and Ping Che and Riccardo Hertel and Teruo Ono and Dmytro Afanasiev and Johan Mentink and Theo Rasing and Burkard Hillebrands and Silvia Viola Kusminskiy and Wei Zhang and Chunhui Rita Du and Aurore Finco and Toeno van der Sar and Yunqiu Kelly Luo and Yoichi Shiota and Joseph Sklenar and Tao Yu and Jinwei Rao}, url = {`}, doi = {10.1088/1361-648X/ad399c}, year = {2024}, date = {2024-06-14}, journal = {Journal of Physics: Condensed Matter}, volume = {36}, number = {36}, pages = {363501}, publisher = {IOP Publishing}, abstract = {Magnonics is a research field that has gained an increasing interest in both the fundamental and applied sciences in recent years. This field aims to explore and functionalize collective spin excitations in magnetically ordered materials for modern information technologies, sensing applications and advanced computational schemes. Spin waves, also known as magnons, carry spin angular momenta that allow for the transmission, storage and processing of information without moving charges. In integrated circuits, magnons enable on-chip data processing at ultrahigh frequencies without the Joule heating, which currently limits clock frequencies in conventional data processors to a few GHz. Recent developments in the field indicate that functional magnonic building blocks for in-memory computation, neural networks and Ising machines are within reach. At the same time, the miniaturization of magnonic circuits advances continuously as the synergy of materials science, electrical engineering and nanotechnology allows for novel on-chip excitation and detection schemes. Such circuits can already enable magnon wavelengths of 50 nm at microwave frequencies in a 5G frequency band. Research into non-charge-based technologies is urgently needed in view of the rapid growth of machine learning and artificial intelligence applications, which consume substantial energy when implemented on conventional data processing units. In its first part, the 2024 Magnonics Roadmap provides an update on the recent developments and achievements in the field of nano-magnonics while defining its future avenues and challenges. In its second part, the Roadmap addresses the rapidly growing research endeavors on hybrid structures and magnonics-enabled quantum engineering. We anticipate that these directions will continue to attract researchers to the field and, in addition to showcasing intriguing science, will enable unprecedented functionalities that enhance the efficiency of alternative information technologies and computational schemes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Magnonics is a research field that has gained an increasing interest in both the fundamental and applied sciences in recent years. This field aims to explore and functionalize collective spin excitations in magnetically ordered materials for modern information technologies, sensing applications and advanced computational schemes. Spin waves, also known as magnons, carry spin angular momenta that allow for the transmission, storage and processing of information without moving charges. In integrated circuits, magnons enable on-chip data processing at ultrahigh frequencies without the Joule heating, which currently limits clock frequencies in conventional data processors to a few GHz. Recent developments in the field indicate that functional magnonic building blocks for in-memory computation, neural networks and Ising machines are within reach. At the same time, the miniaturization of magnonic circuits advances continuously as the synergy of materials science, electrical engineering and nanotechnology allows for novel on-chip excitation and detection schemes. Such circuits can already enable magnon wavelengths of 50 nm at microwave frequencies in a 5G frequency band. Research into non-charge-based technologies is urgently needed in view of the rapid growth of machine learning and artificial intelligence applications, which consume substantial energy when implemented on conventional data processing units. In its first part, the 2024 Magnonics Roadmap provides an update on the recent developments and achievements in the field of nano-magnonics while defining its future avenues and challenges. In its second part, the Roadmap addresses the rapidly growing research endeavors on hybrid structures and magnonics-enabled quantum engineering. We anticipate that these directions will continue to attract researchers to the field and, in addition to showcasing intriguing science, will enable unprecedented functionalities that enhance the efficiency of alternative information technologies and computational schemes. |
| 247. | Mutlu Gokkavas, T. F. Gundogdu, Ekmel Ozbay, Andriy E. Serebryannikov Scientific Reports, 14 (1), pp. 13636, 2024, ISSN: 2045-2322. @article{gokkavas_few-layer_2024, title = {Few-layer bifunctional metasurfaces enabling asymmetric and symmetric polarization-plane rotation at the subwavelength scale}, author = {Mutlu Gokkavas and T. F. Gundogdu and Ekmel Ozbay and Andriy E. Serebryannikov}, url = {https://www.nature.com/articles/s41598-024-62073-4}, doi = {10.1038/s41598-024-62073-4}, issn = {2045-2322}, year = {2024}, date = {2024-06-13}, urldate = {2024-06-13}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {13636}, abstract = {We introduce and numerically validate the concept of few-layer bifunctional metasurfaces comprising two arrays of quasiplanar subwavelength resonators and a middle grid (array of rectangular holes) that offer both symmetric and asymmetric transmissions connected, respectively, with symmetric and asymmetric polarization-plane rotation functionalities. The proposed structures are thinner than $$textbackslashlambda /7$$and free of diffractions. Usually, the structure’s symmetry or asymmetry, i.e. unbroken or broken spatial inversion symmetries, are considered for metasurfaces as prerequisites of the capability of symmetric or asymmetric conversion of linearly polarized waves, respectively. Due to the achieved adjustment of the resonances enabling the rotation of the polarization plane simultaneously for both orthogonal polarizations of the incident wave, the symmetric polarization-plane rotation functionality can be obtained within one subwavelength band, whereas the asymmetric polarization-plane rotation functionality associated with the asymmetric transmission is obtained within another subwavelength band. This combination of the functionalities in one subdiffraction structure is possible due to the optimal choice of the grid parameters, since they may strongly affect the coupling between the two resonator arrays. Although normal incidence is required for the targeted bifunctionality, the variations of the incidence angle can also be exploited for the enrichment of the overall functional capability. Variations of the polarization angle give another important degree of freedom. The connection between the polarization-angle dependence of cross-polarized transmission and capability of symmetric and asymmetric polarization-plane rotation functionalities is highlighted. The feasible designs of the bifunctional metasurfaces are discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We introduce and numerically validate the concept of few-layer bifunctional metasurfaces comprising two arrays of quasiplanar subwavelength resonators and a middle grid (array of rectangular holes) that offer both symmetric and asymmetric transmissions connected, respectively, with symmetric and asymmetric polarization-plane rotation functionalities. The proposed structures are thinner than $$textbackslashlambda /7$$and free of diffractions. Usually, the structure’s symmetry or asymmetry, i.e. unbroken or broken spatial inversion symmetries, are considered for metasurfaces as prerequisites of the capability of symmetric or asymmetric conversion of linearly polarized waves, respectively. Due to the achieved adjustment of the resonances enabling the rotation of the polarization plane simultaneously for both orthogonal polarizations of the incident wave, the symmetric polarization-plane rotation functionality can be obtained within one subwavelength band, whereas the asymmetric polarization-plane rotation functionality associated with the asymmetric transmission is obtained within another subwavelength band. This combination of the functionalities in one subdiffraction structure is possible due to the optimal choice of the grid parameters, since they may strongly affect the coupling between the two resonator arrays. Although normal incidence is required for the targeted bifunctionality, the variations of the incidence angle can also be exploited for the enrichment of the overall functional capability. Variations of the polarization angle give another important degree of freedom. The connection between the polarization-angle dependence of cross-polarized transmission and capability of symmetric and asymmetric polarization-plane rotation functionalities is highlighted. The feasible designs of the bifunctional metasurfaces are discussed. |
| 246. | Julia Kharlan, Krzysztof Sobucki, Krzysztof Szulc, Sara Memarzadeh, Jarosław W. Kłos Spin-wave confinement in a hybrid superconductor-ferrimagnet nanostructure Phys. Rev. Appl., 21 , pp. 064007, 2024. @article{PhysRevApplied.21.064007, title = {Spin-wave confinement in a hybrid superconductor-ferrimagnet nanostructure}, author = {Julia Kharlan and Krzysztof Sobucki and Krzysztof Szulc and Sara Memarzadeh and Jarosław W. Kłos}, url = {https://link.aps.org/doi/10.1103/PhysRevApplied.21.064007}, doi = {10.1103/PhysRevApplied.21.064007}, year = {2024}, date = {2024-06-05}, journal = {Phys. Rev. Appl.}, volume = {21}, pages = {064007}, publisher = {American Physical Society}, abstract = {Eddy currents in a superconductor shield the magnetic field in its interior and are responsible for the formation of a magnetic stray field outside of the superconducting structure. The stray field can be controlled by the external magnetic field and affect the magnetization dynamics in the magnetic system placed in its range. In the case of a hybrid system consisting of a superconducting strip placed over a magnetic layer, we theoretically predict the confinement of spin waves in the well of the static stray field. The number of bound states and their frequencies can be controlled by an external magnetic field. We present the results of semianalytical calculations complemented by numerical modeling.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eddy currents in a superconductor shield the magnetic field in its interior and are responsible for the formation of a magnetic stray field outside of the superconducting structure. The stray field can be controlled by the external magnetic field and affect the magnetization dynamics in the magnetic system placed in its range. In the case of a hybrid system consisting of a superconducting strip placed over a magnetic layer, we theoretically predict the confinement of spin waves in the well of the static stray field. The number of bound states and their frequencies can be controlled by an external magnetic field. We present the results of semianalytical calculations complemented by numerical modeling. |
| 245. | Weronika Andrzejewska, Paweł Wojciechowski, Mariya V Dobrotvorska, Szymon Murawka, Paweł Sobieszczyk, Mateusz Zelent, Mikołaj Lewandowski Directional growth of iron oxide nanowires on a vicinal copper surface Journal of Physics: Condensed Matter, 36 (34), pp. 345004, 2024. @article{Andrzejewska_2024, title = {Directional growth of iron oxide nanowires on a vicinal copper surface}, author = {Weronika Andrzejewska and Paweł Wojciechowski and Mariya V Dobrotvorska and Szymon Murawka and Paweł Sobieszczyk and Mateusz Zelent and Mikołaj Lewandowski}, url = {https://dx.doi.org/10.1088/1361-648X/ad3e58}, doi = {10.1088/1361-648X/ad3e58}, year = {2024}, date = {2024-05-30}, journal = {Journal of Physics: Condensed Matter}, volume = {36}, number = {34}, pages = {345004}, publisher = {IOP Publishing}, abstract = {Single-crystal magnetic nanostructures with well-defined shapes attract lots of interest due to their potential applications in magnetic and spintronic devices. However, development of methods allowing controlling their mutual crystallographic and geometric orientation constitutes a significant scientific challenge. One of the routes for obtaining such structures is to grow the materials epitaxially on naturally-structured supports, such as vicinal surfaces of single-crystal substrates. Iron oxides are among the most well-known magnetic materials which, depending on the phase, may exhibit ferro/ferri- or antiferromagnetic ordering. We have grown iron oxide nanowires on a Cu(410) single-crystal substrate faceted with molecular oxygen. Scanning tunneling microscopy and low energy electron diffraction revealed that the oxide grows in the [111] direction, along the step edges of the substrate and rotated by ±15° with respect to the [010] direction of copper atomic terraces (so that the the growing elongated structures are orientated parallel to each other). Notably, x-ray photoelectron spectroscopy confirmed that the nanowires represent the ferrimagnetic γ-Fe2O3 (maghemite) iron oxide phase, while micromagnetic simulations indicated that the wires are single-domain, with the easy magnetization axis orientated in-plane and along the long axis of the wire.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Single-crystal magnetic nanostructures with well-defined shapes attract lots of interest due to their potential applications in magnetic and spintronic devices. However, development of methods allowing controlling their mutual crystallographic and geometric orientation constitutes a significant scientific challenge. One of the routes for obtaining such structures is to grow the materials epitaxially on naturally-structured supports, such as vicinal surfaces of single-crystal substrates. Iron oxides are among the most well-known magnetic materials which, depending on the phase, may exhibit ferro/ferri- or antiferromagnetic ordering. We have grown iron oxide nanowires on a Cu(410) single-crystal substrate faceted with molecular oxygen. Scanning tunneling microscopy and low energy electron diffraction revealed that the oxide grows in the [111] direction, along the step edges of the substrate and rotated by ±15° with respect to the [010] direction of copper atomic terraces (so that the the growing elongated structures are orientated parallel to each other). Notably, x-ray photoelectron spectroscopy confirmed that the nanowires represent the ferrimagnetic γ-Fe2O3 (maghemite) iron oxide phase, while micromagnetic simulations indicated that the wires are single-domain, with the easy magnetization axis orientated in-plane and along the long axis of the wire. |
| 244. | Mathieu Moalic, Mateusz Zelent, Krzysztof Szulc, Maciej Krawczyk The role of non-uniform magnetization texture for magnon–magnon coupling in an antidot lattice Scientific Reports, 14 (1), pp. 11501, 2024, ISSN: 2045-2322. @article{moalic_role_2024, title = {The role of non-uniform magnetization texture for magnon–magnon coupling in an antidot lattice}, author = {Mathieu Moalic and Mateusz Zelent and Krzysztof Szulc and Maciej Krawczyk}, url = {https://www.nature.com/articles/s41598-024-61246-5}, doi = {10.1038/s41598-024-61246-5}, issn = {2045-2322}, year = {2024}, date = {2024-05-20}, urldate = {2024-05-23}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {11501}, abstract = {We numerically study the spin-wave dynamics in an antidot lattice based on a Co/Pd multilayer structure with reduced perpendicular magnetic anisotropy at the edges of the antidots. This structure forms a magnonic crystal with a periodic antidot pattern and a periodic magnetization configuration consisting of out-of-plane magnetized bulk and in-plane magnetized rims. Our results show a different behavior of spin waves in the bulk and in the rims under varying out-of-plane external magnetic field strength, revealing complex spin-wave spectra and hybridizations between the modes of these two subsystems. A particularly strong magnon–magnon coupling, due to exchange interactions, is found between the fundamental bulk spin-wave mode and the second-order radial rim modes. However, the dynamical coupling between the spin-wave modes at low frequencies, involving the first-order radial rim modes, is masked by the changes in the static magnetization at the bulk–rim interface with magnetic field changes. The study expands the horizons of magnonic-crystal research by combining periodic structural patterning and non-collinear magnetization texture to achieve strong magnon–magnon coupling, highlighting the significant role of exchange interactions in the hybridization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We numerically study the spin-wave dynamics in an antidot lattice based on a Co/Pd multilayer structure with reduced perpendicular magnetic anisotropy at the edges of the antidots. This structure forms a magnonic crystal with a periodic antidot pattern and a periodic magnetization configuration consisting of out-of-plane magnetized bulk and in-plane magnetized rims. Our results show a different behavior of spin waves in the bulk and in the rims under varying out-of-plane external magnetic field strength, revealing complex spin-wave spectra and hybridizations between the modes of these two subsystems. A particularly strong magnon–magnon coupling, due to exchange interactions, is found between the fundamental bulk spin-wave mode and the second-order radial rim modes. However, the dynamical coupling between the spin-wave modes at low frequencies, involving the first-order radial rim modes, is masked by the changes in the static magnetization at the bulk–rim interface with magnetic field changes. The study expands the horizons of magnonic-crystal research by combining periodic structural patterning and non-collinear magnetization texture to achieve strong magnon–magnon coupling, highlighting the significant role of exchange interactions in the hybridization. |
| 243. | Uladzislau Makartsou, Mateusz Gołębiewski, Urszula Guzowska, Alexander Stognij, Ryszard Gieniusz, Maciej Krawczyk Applied Physics Letters, 124 (19), pp. 192406, 2024, ISSN: 0003-6951. @article{10.1063/5.0195099, title = {Spin-wave self-imaging: Experimental and numerical demonstration of caustic and Talbot-like diffraction patterns}, author = {Uladzislau Makartsou and Mateusz Gołębiewski and Urszula Guzowska and Alexander Stognij and Ryszard Gieniusz and Maciej Krawczyk}, url = {https://doi.org/10.1063/5.0195099}, doi = {10.1063/5.0195099}, issn = {0003-6951}, year = {2024}, date = {2024-05-09}, journal = {Applied Physics Letters}, volume = {124}, number = {19}, pages = {192406}, abstract = {Extending the scope of the self-imaging phenomenon, traditionally associated with linear optics, to the domain of magnonics, this study presents the experimental demonstration and numerical analysis of spin-wave (SW) self-imaging in an in-plane magnetized yttrium iron garnet film. We explore this phenomenon using a setup in which a plane SW passes through a diffraction grating, and the resulting interference pattern is detected using Brillouin light scattering. We have varied the frequencies of the source dynamic magnetic field to discern the influence of the anisotropic dispersion relation and the caustic effect on the analyzed phenomenon. We found that at low frequencies and diffraction fields, the caustics determine the interference pattern. However, at large distances from the grating, when the waves of high diffraction order and number of slits contribute to the interference pattern, the self-imaging phenomenon and Talbot-like patterns are formed. This methodological approach not only sheds light on the behavior of SW interference under different conditions but also enhances our understanding of the SW self-imaging process in both isotropic and anisotropic media.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Extending the scope of the self-imaging phenomenon, traditionally associated with linear optics, to the domain of magnonics, this study presents the experimental demonstration and numerical analysis of spin-wave (SW) self-imaging in an in-plane magnetized yttrium iron garnet film. We explore this phenomenon using a setup in which a plane SW passes through a diffraction grating, and the resulting interference pattern is detected using Brillouin light scattering. We have varied the frequencies of the source dynamic magnetic field to discern the influence of the anisotropic dispersion relation and the caustic effect on the analyzed phenomenon. We found that at low frequencies and diffraction fields, the caustics determine the interference pattern. However, at large distances from the grating, when the waves of high diffraction order and number of slits contribute to the interference pattern, the self-imaging phenomenon and Talbot-like patterns are formed. This methodological approach not only sheds light on the behavior of SW interference under different conditions but also enhances our understanding of the SW self-imaging process in both isotropic and anisotropic media. |
| 242. | Agata Krzywicka, Tomasz P Polak Reentrant phase behavior in systems with density-induced tunneling Scientific Reports, 14 , pp. 10364 , 2024. @article{Krzywicka2024, title = {Reentrant phase behavior in systems with density-induced tunneling}, author = {Agata Krzywicka and Tomasz P Polak}, doi = {10.1038/s41598-024-60955-1}, year = {2024}, date = {2024-05-06}, journal = {Scientific Reports}, volume = {14}, pages = {10364 }, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 241. | Javier Argüello-Luengo, Utso Bhattacharya, Alessio Celi, Ravindra W. Chhajlany, Tobias Graß, Marcin Płodzień, Debraj Rakshit, Tymoteusz Salamon, Paolo Stornati, Leticia Tarruell, Maciej Lewenstein Synthetic dimensions for topological and quantum phases Communications Physics, 7 (1), pp. 143, 2024. @article{Arguello-Luengo2024-ip, title = {Synthetic dimensions for topological and quantum phases}, author = {Javier Argüello-Luengo and Utso Bhattacharya and Alessio Celi and Ravindra W. Chhajlany and Tobias Graß and Marcin P{ł}odzie{ń} and Debraj Rakshit and Tymoteusz Salamon and Paolo Stornati and Leticia Tarruell and Maciej Lewenstein}, url = {https://www.nature.com/articles/s42005-024-01636-3#citeas}, doi = {10.1038/s42005-024-01636-3}, year = {2024}, date = {2024-05-04}, journal = {Communications Physics}, volume = {7}, number = {1}, pages = {143}, abstract = {The concept of synthetic dimensions works particularly well in atomic physics, quantum optics, and photonics, where the internal degrees of freedom (Zeeman sublevels of the ground state, metastable excited states, or motional states for atoms, and angular momentum states or transverse modes for photons) provide the synthetic space. In this Perspective article we report on recent progress on studies of synthetic dimensions, mostly, but not only, based on the research realized around the Barcelona groups (ICFO, UAB), Donostia (DIPC), Poznan (UAM), Kraków (UJ), and Allahabad (HRI). We describe our attempts to design quantum simulators with synthetic dimensions, to mimic curved spaces, artificial gauge fields, lattice gauge theories, twistronics, quantum random walks, and more.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The concept of synthetic dimensions works particularly well in atomic physics, quantum optics, and photonics, where the internal degrees of freedom (Zeeman sublevels of the ground state, metastable excited states, or motional states for atoms, and angular momentum states or transverse modes for photons) provide the synthetic space. In this Perspective article we report on recent progress on studies of synthetic dimensions, mostly, but not only, based on the research realized around the Barcelona groups (ICFO, UAB), Donostia (DIPC), Poznan (UAM), Kraków (UJ), and Allahabad (HRI). We describe our attempts to design quantum simulators with synthetic dimensions, to mimic curved spaces, artificial gauge fields, lattice gauge theories, twistronics, quantum random walks, and more. |
| 240. | Bárbara Andrade, Utso Bhattacharya, Ravindra W. Chhajlany, Tobias Graß, Maciej Lewenstein Observing quantum many-body scars in random quantum circuits Phys. Rev. A, 109 , pp. 052602, 2024. @article{PhysRevA.109.052602, title = {Observing quantum many-body scars in random quantum circuits}, author = {Bárbara Andrade and Utso Bhattacharya and Ravindra W. Chhajlany and Tobias Graß{} and Maciej Lewenstein}, url = {https://link.aps.org/doi/10.1103/PhysRevA.109.052602}, doi = {10.1103/PhysRevA.109.052602}, year = {2024}, date = {2024-05-01}, journal = {Phys. Rev. A}, volume = {109}, pages = {052602}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 239. | Mateusz Gołębiewski, Riccardo Hertel, Massimiliano dÁquino, Vitaliy Vasyuchka, Mathias Weiler, Philipp Pirro, Maciej Krawczyk, Shunsuke Fukami, Hideo Ohno, Justin Llandro Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures ACS Applied Materials & Interfaces, 2024, ISSN: 1944-8244. @article{Gołębiewski2024, title = {Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures}, author = {Mateusz Gołębiewski and Riccardo Hertel and Massimiliano dÁquino and Vitaliy Vasyuchka and Mathias Weiler and Philipp Pirro and Maciej Krawczyk and Shunsuke Fukami and Hideo Ohno and Justin Llandro}, url = {https://doi.org/10.1021/acsami.4c02366}, doi = {10.1021/acsami.4c02366}, issn = {1944-8244}, year = {2024}, date = {2024-04-22}, journal = {ACS Applied Materials & Interfaces}, publisher = {American Chemical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 238. | Piotr Trocha, Thibaut Jonckheere, Jérôme Rech, Thierry Martin Journal of Magnetism and Magnetic Materials, 596 , pp. 171922, 2024. @article{Trocha2024, title = {Out-of-equilibrium voltage and thermal bias response of a quantum dot hybrid system coupled to topological superconductor}, author = {Piotr Trocha and Thibaut Jonckheere and Jérôme Rech and Thierry Martin}, url = {https://www.sciencedirect.com/science/article/pii/S0304885324002130?via%3Dihub}, doi = {/10.1016/j.jmmm.2024.171922}, year = {2024}, date = {2024-04-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {596}, pages = {171922}, abstract = {We investigate theoretically the out-of-equilibrium transport properties of a single-level quantum dot coupled to a normal metal electrode and attached to a topological superconductor. Both voltage and thermal bias responses of the system in the nonequilibrium regime are studied. To obtain transport characteristics we used the nonequilibrium Green’s function approach. Particularly, we calculated the current and the corresponding differential conductance in two distinct cases. In the former situation, the charge current is induced by applying a bias voltage, whereas in the latter case it is generated by setting a temperature difference between the leads with no bias voltage. Moreover, strong diode effect in thermally generated current is found and non-equilibrium thermopower is analyzed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate theoretically the out-of-equilibrium transport properties of a single-level quantum dot coupled to a normal metal electrode and attached to a topological superconductor. Both voltage and thermal bias responses of the system in the nonequilibrium regime are studied. To obtain transport characteristics we used the nonequilibrium Green’s function approach. Particularly, we calculated the current and the corresponding differential conductance in two distinct cases. In the former situation, the charge current is induced by applying a bias voltage, whereas in the latter case it is generated by setting a temperature difference between the leads with no bias voltage. Moreover, strong diode effect in thermally generated current is found and non-equilibrium thermopower is analyzed. |
| 237. | Deng-Gao Lai, C.-H. Wang, B.-P. Hou, Adam Miranowicz, Franco Nori Exceptional refrigeration of motions beyond their mass and temperature limitations Optica, 11 (4), pp. 485-491, 2024. @article{Lai2024, title = {Exceptional refrigeration of motions beyond their mass and temperature limitations}, author = {Deng-Gao Lai and C.-H. Wang and B.-P. Hou and Adam Miranowicz and Franco Nori}, url = {https://opg.optica.org/optica/abstract.cfm?URI=optica-11-4-485}, doi = {10.1364/OPTICA.495199}, year = {2024}, date = {2024-04-08}, journal = {Optica}, volume = {11}, number = {4}, pages = {485-491}, abstract = {Coaxing vibrations in the regimes of both large mass and high temperature into their motional quantum ground states is extremely challenging, because it requires an ultra-high optical power, which introduces extraneous excessive heating and intricate instabilities. Here we propose how to overcome these obstacles and cool vibrational networks by simply harnessing the power of an exceptional point (EP) induced in parity-time symmetric structures; and we reveal its exceptional cooling properties otherwise unachievable in conventional devices. In stark contrast to standard-cooling protocols, a three orders-of-magnitude amplification in net cooling rates arises from the EP-cooling mechanism, without which it vanishes. Remarkably, our EP cooling is nearly immune to both resonator mass and environmental temperature, and this overthrows the consensus that poor intrinsic factors and rugged extrinsic environment suppress cooling channels. Our study offers the possibility of isolating and engineering motional properties of large-mass and high-temperature objects for various applications in optical and acoustic sensing, gravimetry, and inertial navigation.}, }, keywords = {}, pubstate = {published}, tppubtype = {article} } Coaxing vibrations in the regimes of both large mass and high temperature into their motional quantum ground states is extremely challenging, because it requires an ultra-high optical power, which introduces extraneous excessive heating and intricate instabilities. Here we propose how to overcome these obstacles and cool vibrational networks by simply harnessing the power of an exceptional point (EP) induced in parity-time symmetric structures; and we reveal its exceptional cooling properties otherwise unachievable in conventional devices. In stark contrast to standard-cooling protocols, a three orders-of-magnitude amplification in net cooling rates arises from the EP-cooling mechanism, without which it vanishes. Remarkably, our EP cooling is nearly immune to both resonator mass and environmental temperature, and this overthrows the consensus that poor intrinsic factors and rugged extrinsic environment suppress cooling channels. Our study offers the possibility of isolating and engineering motional properties of large-mass and high-temperature objects for various applications in optical and acoustic sensing, gravimetry, and inertial navigation.}, |
| 236. | Kacper Wrześniewski, Ireneusz Weymann Scientific Reports, 14 (7815), 2024. @article{Wrześniewski2024, title = {Cross-correlations between currents and tunnel magnetoresistance in interacting double quantum dot-Majorana wire system}, author = {Kacper Wrześniewski and Ireneusz Weymann }, url = {https://link.springer.com/article/10.1038/s41598-024-58344-9}, doi = {10.1038/s41598-024-58344-9}, year = {2024}, date = {2024-04-03}, journal = {Scientific Reports}, volume = {14}, number = {7815}, abstract = {We theoretically investigate the spin and charge transport properties of a double quantum dot coupled to distinct edges of the nanowire hosting Majorana zero-energy modes. The focus is on the analysis of the currents flowing through the left and right junctions and their cross-correlations. We show that the system reveals very different transport properties depending on the detuning protocol of the quantum dot energy levels. For the symmetric detuning, the current dependencies reveal only two maxima associated with resonant tunneling, and currents in the left and right arms of the system reveal weak positive cross-correlations. On the other hand, for antisymmetric detuning, the flow of electrons into drains is maximized and strongly correlated in one bias voltage direction, while for the opposite bias direction a spin blockade is predicted. Furthermore, we observe a suppression of the current cross-correlations at a highly symmetric detuning point, indicating the involvement of the Majorana zero-energy modes in the transport processes. To gain insight into the role of the spin polarization of the Majorana edge states, we analyze the spin-dependent transport characteristics by considering the relationship between the spin canting angle, which describes the coupling of the Majorana modes to the spin of the quantum dots, and the magnetic configurations of the ferromagnetic drains. Moreover, we examine the non-local zero bias anomaly in the differential conductance, detailed analysis of which revealed a specific operational mode of the device that can facilitate the identification of the Majorana presence in the quantum dot-Majorana wire system. Finally, we also consider the transport properties in different magnetic configurations of the system and discuss the behavior of the associated tunnel magnetoresistance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We theoretically investigate the spin and charge transport properties of a double quantum dot coupled to distinct edges of the nanowire hosting Majorana zero-energy modes. The focus is on the analysis of the currents flowing through the left and right junctions and their cross-correlations. We show that the system reveals very different transport properties depending on the detuning protocol of the quantum dot energy levels. For the symmetric detuning, the current dependencies reveal only two maxima associated with resonant tunneling, and currents in the left and right arms of the system reveal weak positive cross-correlations. On the other hand, for antisymmetric detuning, the flow of electrons into drains is maximized and strongly correlated in one bias voltage direction, while for the opposite bias direction a spin blockade is predicted. Furthermore, we observe a suppression of the current cross-correlations at a highly symmetric detuning point, indicating the involvement of the Majorana zero-energy modes in the transport processes. To gain insight into the role of the spin polarization of the Majorana edge states, we analyze the spin-dependent transport characteristics by considering the relationship between the spin canting angle, which describes the coupling of the Majorana modes to the spin of the quantum dots, and the magnetic configurations of the ferromagnetic drains. Moreover, we examine the non-local zero bias anomaly in the differential conductance, detailed analysis of which revealed a specific operational mode of the device that can facilitate the identification of the Majorana presence in the quantum dot-Majorana wire system. Finally, we also consider the transport properties in different magnetic configurations of the system and discuss the behavior of the associated tunnel magnetoresistance. |
| 235. | Nikhil Kumar, Paweł Gruszecki, Mateusz Gołębiewski, Jarosław W. Kłos, Maciej Krawczyk Exciting High-Frequency Short-Wavelength Spin Waves using High Harmonics of a Magnonic Cavity Mode Advanced Quantum Technologies, n/a (n/a), pp. 2400015, 2024. @article{https://doi.org/10.1002/qute.202400015, title = {Exciting High-Frequency Short-Wavelength Spin Waves using High Harmonics of a Magnonic Cavity Mode}, author = {Nikhil Kumar and Paweł Gruszecki and Mateusz Gołębiewski and Jarosław W. Kłos and Maciej Krawczyk}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202400015}, doi = {https://doi.org/10.1002/qute.202400015}, year = {2024}, date = {2024-03-29}, journal = {Advanced Quantum Technologies}, volume = {n/a}, number = {n/a}, pages = {2400015}, abstract = {Abstract Spin waves (SWs) are promising objects for signal processing and future quantum technologies due to their high microwave frequencies with corresponding nanoscale wavelengths. However, the nano-wavelength SWs generated so far are limited to low frequencies. In the paper, using micromagnetic simulations, it is shown that a microwave-pumped SW mode confined to the cavity of a thin film magnonic crystal (MC) can be used to generate waves at tens of GHz and wavelengths well below 50 nm. These multi-frequency harmonics of the fundamental cavity mode are generated when the amplitude of the pumping microwave field exceeds a threshold, and their intensities then scale linearly with the field intensity. The frequency of the cavity mode is equal to the ferromagnetic resonance frequency of the planar ferromagnetic film, which overlaps with the magnonic bandgap, providing an efficient mechanism for confinement and magnetic field tunability. The effect reaches saturation when the microstrip feed line covers the entire cavity, making the system feasible for realization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract Spin waves (SWs) are promising objects for signal processing and future quantum technologies due to their high microwave frequencies with corresponding nanoscale wavelengths. However, the nano-wavelength SWs generated so far are limited to low frequencies. In the paper, using micromagnetic simulations, it is shown that a microwave-pumped SW mode confined to the cavity of a thin film magnonic crystal (MC) can be used to generate waves at tens of GHz and wavelengths well below 50 nm. These multi-frequency harmonics of the fundamental cavity mode are generated when the amplitude of the pumping microwave field exceeds a threshold, and their intensities then scale linearly with the field intensity. The frequency of the cavity mode is equal to the ferromagnetic resonance frequency of the planar ferromagnetic film, which overlaps with the magnonic bandgap, providing an efficient mechanism for confinement and magnetic field tunability. The effect reaches saturation when the microstrip feed line covers the entire cavity, making the system feasible for realization. |
| 234. | Chia-Yi Ju, Adam Miranowicz, Yueh-Nan Chen, Guang-Yin Chen, Franco Nori Emergent parallel transport and curvature in Hermitian and non-Hermitian quantum mechanics Quantum, 8 , pp. 1277, 2024. @article{Ju2024, title = {Emergent parallel transport and curvature in Hermitian and non-Hermitian quantum mechanics}, author = {Chia-Yi Ju and Adam Miranowicz and Yueh-Nan Chen and Guang-Yin Chen and Franco Nori}, url = {https://quantum-journal.org/papers/q-2024-03-13-1277/}, doi = {10.22331/q-2024-03-13-1277}, year = {2024}, date = {2024-03-13}, journal = {Quantum}, volume = {8}, pages = {1277}, abstract = {Studies have shown that the Hilbert spaces of non-Hermitian systems require nontrivial metrics. Here, we demonstrate how evolution dimensions, in addition to time, can emerge naturally from a geometric formalism. Specifically, in this formalism, Hamiltonians can be interpreted as a Christoffel symbol-like operators, and the Schroedinger equation as a parallel transport in this formalism. We then derive the evolution equations for the states and metrics along the emergent dimensions and find that the curvature of the Hilbert space bundle for any given closed system is locally flat. Finally, we show that the fidelity susceptibilities and the Berry curvatures of states are related to these emergent parallel transports.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Studies have shown that the Hilbert spaces of non-Hermitian systems require nontrivial metrics. Here, we demonstrate how evolution dimensions, in addition to time, can emerge naturally from a geometric formalism. Specifically, in this formalism, Hamiltonians can be interpreted as a Christoffel symbol-like operators, and the Schroedinger equation as a parallel transport in this formalism. We then derive the evolution equations for the states and metrics along the emergent dimensions and find that the curvature of the Hilbert space bundle for any given closed system is locally flat. Finally, we show that the fidelity susceptibilities and the Berry curvatures of states are related to these emergent parallel transports. |
| 233. | Arnab Laha, Adam Miranowicz, R. K. Varshney, Somnath Ghosh Correlated nonreciprocity around conjugate exceptional points Phys. Rev. A, 109 , pp. 033511, 2024. @article{Laha2024, title = {Correlated nonreciprocity around conjugate exceptional points}, author = {Arnab Laha and Adam Miranowicz and R. K. Varshney and Somnath Ghosh}, url = {https://link.aps.org/doi/10.1103/PhysRevA.109.033511}, doi = {10.1103/PhysRevA.109.033511}, year = {2024}, date = {2024-03-08}, journal = {Phys. Rev. A}, volume = {109}, pages = {033511}, abstract = {The occurrence of exceptional points (EPs) is a fascinating non-Hermitian feature of open systems. A level-repulsion phenomenon between two complex states of an open system can be realized by positioning an EP and its time-reversal ( T ) conjugate pair in the underlying parameter space. Here, we report interesting nonreciprocal responses of such two conjugate EPs by using a dual-mode planar waveguide system having two T -symmetric active variants concerning the transverse gain-loss profiles. We specifically reveal an all-optical scheme to achieve correlative nonreciprocal light dynamics by using the reverse chirality of two dynamically encircled conjugate EPs in the presence of local nonlinearity. A specific nonreciprocal correlation between two designed T -symmetric waveguide variants is established in terms of their unidirectional transfer of light with a precise selection of modes. Here, the unconventional reverse chiral properties of two conjugate EPs allow the nonreciprocal transmission of two selective modes in the opposite directions of the underlying waveguide variants. An explicit dependence of the nonlinearity level on a significant enhancement of the nonreciprocity in terms of an isolation ratio is explored by investigating the effects of both local Kerr-type and saturable nonlinearities (considered separately). The physical insights and implications of harnessing the features of conjugate EPs in nonlinear optical systems can enable the growth and development of a versatile platform for building nonreciprocal components and devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The occurrence of exceptional points (EPs) is a fascinating non-Hermitian feature of open systems. A level-repulsion phenomenon between two complex states of an open system can be realized by positioning an EP and its time-reversal ( T ) conjugate pair in the underlying parameter space. Here, we report interesting nonreciprocal responses of such two conjugate EPs by using a dual-mode planar waveguide system having two T -symmetric active variants concerning the transverse gain-loss profiles. We specifically reveal an all-optical scheme to achieve correlative nonreciprocal light dynamics by using the reverse chirality of two dynamically encircled conjugate EPs in the presence of local nonlinearity. A specific nonreciprocal correlation between two designed T -symmetric waveguide variants is established in terms of their unidirectional transfer of light with a precise selection of modes. Here, the unconventional reverse chiral properties of two conjugate EPs allow the nonreciprocal transmission of two selective modes in the opposite directions of the underlying waveguide variants. An explicit dependence of the nonlinearity level on a significant enhancement of the nonreciprocity in terms of an isolation ratio is explored by investigating the effects of both local Kerr-type and saturable nonlinearities (considered separately). The physical insights and implications of harnessing the features of conjugate EPs in nonlinear optical systems can enable the growth and development of a versatile platform for building nonreciprocal components and devices. |
| 232. | Wei Qin, Adam Miranowicz, Franco Nori Proposal of ensemble qubits with two-atom decay New Journal of Physics, 26 , pp. 033006, 2024. @article{Qin2024, title = {Proposal of ensemble qubits with two-atom decay}, author = {Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://iopscience.iop.org/article/10.1088/1367-2630/ad2bad}, doi = {10.1088/1367-2630/ad2bad}, year = {2024}, date = {2024-03-08}, journal = {New Journal of Physics}, volume = {26}, pages = {033006}, abstract = {We propose and analyze a novel approach to implement ensemble qubits. The required anharmonicity is provided by a simultaneous decay of two atoms (i.e. two-atom decay), which is achieved by fully quantum degenerate parametric amplification. For an atomic ensemble, the two-atom decay generates and stabilizes a 2D quantum manifold, which is spanned by the ground and single-excited superradiant states. Moreover, this nonlinear decay process can strongly suppress transitions to higher-excited superradiant states, and convert residual transitions into an effective decay from the single-excitation superradiant state to the ground state. Our method does not require Rydberg dipole blockade and, thus, strong atom-atom interactions, compared to previous work. This indicates that it can be applied to typical atomic or spin ensembles in simple experimental setups. Remarkably, our idea is compatible with the cavity protection mechanism, and therefore spin dephasing due to inhomogeneous broadening can be strongly suppressed. The presented ensemble qubit provides a new platform for quantum information processing, and also extends the range of applications of atomic or spin ensembles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We propose and analyze a novel approach to implement ensemble qubits. The required anharmonicity is provided by a simultaneous decay of two atoms (i.e. two-atom decay), which is achieved by fully quantum degenerate parametric amplification. For an atomic ensemble, the two-atom decay generates and stabilizes a 2D quantum manifold, which is spanned by the ground and single-excited superradiant states. Moreover, this nonlinear decay process can strongly suppress transitions to higher-excited superradiant states, and convert residual transitions into an effective decay from the single-excitation superradiant state to the ground state. Our method does not require Rydberg dipole blockade and, thus, strong atom-atom interactions, compared to previous work. This indicates that it can be applied to typical atomic or spin ensembles in simple experimental setups. Remarkably, our idea is compatible with the cavity protection mechanism, and therefore spin dephasing due to inhomogeneous broadening can be strongly suppressed. The presented ensemble qubit provides a new platform for quantum information processing, and also extends the range of applications of atomic or spin ensembles. |
| 231. | Anand Manaparambil, Ireneusz Weymann Spin-resolved nonequilibrium thermopower of asymmetric nanojunctions Phys. Rev. B, 109 , pp. 115402, 2024. @article{Manaparambil2024b, title = {Spin-resolved nonequilibrium thermopower of asymmetric nanojunctions}, author = {Anand Manaparambil and Ireneusz Weymann}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.109.115402}, doi = {10.1103/PhysRevB.109.115402}, year = {2024}, date = {2024-03-04}, journal = {Phys. Rev. B}, volume = {109}, pages = { 115402}, abstract = {The spin-resolved thermoelectric transport properties of correlated nanoscale junctions, consisting of a quantum dot/molecule asymmetrically coupled to external ferromagnetic contacts, are studied theoretically in the far-from-equilibrium regime. One of the leads is assumed to be strongly coupled to the quantum dot resulting in the development of the Kondo effect. The spin-dependent current flowing through the system, as well as the thermoelectric properties, are calculated by performing a perturbation expansion with respect to the weakly coupled electrode, while the Kondo correlations are captured accurately by using the numerical renormalization group method. In particular, we determine the differential and nonequilibrium Seebeck effects of the considered system in different magnetic configurations and uncover the crucial role of spin-dependent tunneling on the device performance. Moreover, by allowing for the spin accumulation in the leads, which gives rise to finite spin bias, we shed light on the behavior of the nonequilibrium spin Seebeck effect. In particular, we predict new sign changes of the spin-resolved Seebeck effect in the nonlinear response regime, which stem from the interplay of exchange field and finite voltage and temperature gradients.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The spin-resolved thermoelectric transport properties of correlated nanoscale junctions, consisting of a quantum dot/molecule asymmetrically coupled to external ferromagnetic contacts, are studied theoretically in the far-from-equilibrium regime. One of the leads is assumed to be strongly coupled to the quantum dot resulting in the development of the Kondo effect. The spin-dependent current flowing through the system, as well as the thermoelectric properties, are calculated by performing a perturbation expansion with respect to the weakly coupled electrode, while the Kondo correlations are captured accurately by using the numerical renormalization group method. In particular, we determine the differential and nonequilibrium Seebeck effects of the considered system in different magnetic configurations and uncover the crucial role of spin-dependent tunneling on the device performance. Moreover, by allowing for the spin accumulation in the leads, which gives rise to finite spin bias, we shed light on the behavior of the nonequilibrium spin Seebeck effect. In particular, we predict new sign changes of the spin-resolved Seebeck effect in the nonlinear response regime, which stem from the interplay of exchange field and finite voltage and temperature gradients. |
| 230. | Vrishali Sonar, Piotr Trocha Non-local thermoelectric transport in multi-terminal quantum dot hybrid system Journal of Magnetism and Magnetic Materials, 593 , pp. 171745, 2024. @article{Sonar2024, title = {Non-local thermoelectric transport in multi-terminal quantum dot hybrid system}, author = {Vrishali Sonar and Piotr Trocha}, url = {https://www.sciencedirect.com/science/article/pii/S0304885324000350?via%3Dihub}, doi = {10.1016/j.jmmm.2024.171745}, year = {2024}, date = {2024-03-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {593}, pages = {171745}, abstract = {The heat and charge transport is studied in a hybrid multi-terminal device consisting of one metallic, one ferromagnetic and a superconducting lead coupled to quantum dot. The basic thermoelectric properties of the system are examined using non-equilibrium Green’s function method with finite on-dot Coulomb repulsion within Hubbard-I approximation. Local and non-local transport coefficients including electrical and thermal conductance, Seebeck coefficient calculated in the linear response regime. Main objective is to analyze effect of superconductor coupling and ferromagnet’s spin polarization on thermoelectric transport and how ferromagnetic lead modifies it. We also studied the role of different electron tunneling types, i. e. Andreev reflection, quasi-particle and normal single particle tunneling processes on thermoelectric properties of the considered system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The heat and charge transport is studied in a hybrid multi-terminal device consisting of one metallic, one ferromagnetic and a superconducting lead coupled to quantum dot. The basic thermoelectric properties of the system are examined using non-equilibrium Green’s function method with finite on-dot Coulomb repulsion within Hubbard-I approximation. Local and non-local transport coefficients including electrical and thermal conductance, Seebeck coefficient calculated in the linear response regime. Main objective is to analyze effect of superconductor coupling and ferromagnet’s spin polarization on thermoelectric transport and how ferromagnetic lead modifies it. We also studied the role of different electron tunneling types, i. e. Andreev reflection, quasi-particle and normal single particle tunneling processes on thermoelectric properties of the considered system. |
| 229. | Andriy E. Serebryannikov, Akhlesh Lakhtakia, Ekmel Ozbay Opt. Mater. Express, 14 (3), pp. 745–758, 2024. @article{Serebryannikov:24, title = {Thermally mediated transmission-mode deflection of terahertz waves by lamellar metagratings containing a phase-change material}, author = {Andriy E. Serebryannikov and Akhlesh Lakhtakia and Ekmel Ozbay}, url = {https://opg.optica.org/ome/abstract.cfm?URI=ome-14-3-745}, doi = {10.1364/OME.511804}, year = {2024}, date = {2024-03-01}, journal = {Opt. Mater. Express}, volume = {14}, number = {3}, pages = {745--758}, publisher = {Optica Publishing Group}, abstract = {The planewave-response characteristics of simple lamellar metagratings exhibiting thermally mediated transmission-mode deflection (blazing) were numerically investigated, the unit cell of each metagrating containing a phase-change material chosen to be indium antimonide (InSb). Thermal control arises from the use of InSb in its insulator phase and the vicinity of the vacuum state. Metagratings of type A comprise parallel rods of InSb on silicon-dioxide substrate, whereas the substrate is also made of InSb in metagratings of type B. Both types exhibit thermally controllable deflection and asymmetric transmission, which occur when the real part of the relative permittivity of InSb is high. Narrowband features in the sub-diffraction regime may appear in a wide frequency range which involves the vicinity of the vacuum state, the real part of the relative permittivity of InSb being low then.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The planewave-response characteristics of simple lamellar metagratings exhibiting thermally mediated transmission-mode deflection (blazing) were numerically investigated, the unit cell of each metagrating containing a phase-change material chosen to be indium antimonide (InSb). Thermal control arises from the use of InSb in its insulator phase and the vicinity of the vacuum state. Metagratings of type A comprise parallel rods of InSb on silicon-dioxide substrate, whereas the substrate is also made of InSb in metagratings of type B. Both types exhibit thermally controllable deflection and asymmetric transmission, which occur when the real part of the relative permittivity of InSb is high. Narrowband features in the sub-diffraction regime may appear in a wide frequency range which involves the vicinity of the vacuum state, the real part of the relative permittivity of InSb being low then. |
| 228. | Tomasz Kostyrko A DFT+U study of carbon nanotubes under influence of a gate voltage Journal of Magnetism and Magnetic Materials, 593 , pp. 171869, 2024. @article{Kostyrko2024, title = {A DFT+U study of carbon nanotubes under influence of a gate voltage}, author = {Tomasz Kostyrko}, doi = {10.1016/j.jmmm.2024.171869}, year = {2024}, date = {2024-03-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {593}, pages = {171869}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 227. | Yuma Watanabe, Utso Bhattacharya, Ravindra W. Chhajlany, Javier Argüello-Luengo, Maciej Lewenstein, Tobias Graß Competing order in two-band Bose-Hubbard chains with extended-range interactions Phys. Rev. B, 109 , pp. L100507, 2024. @article{PhysRevB.109.L100507, title = {Competing order in two-band Bose-Hubbard chains with extended-range interactions}, author = {Yuma Watanabe and Utso Bhattacharya and Ravindra W. Chhajlany and Javier Argüello-Luengo and Maciej Lewenstein and Tobias Graß}, url = {https://link.aps.org/doi/10.1103/PhysRevB.109.L100507}, doi = {10.1103/PhysRevB.109.L100507}, year = {2024}, date = {2024-03-01}, journal = {Phys. Rev. B}, volume = {109}, pages = {L100507}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 226. | Marek Kopciuch, Magdalena Smolis, Adam Miranowicz, Szymon Pustelny Optimized optical tomography of quantum states of a room-temperature alkali-metal vapor Phys. Rev. A, 109 , pp. 032402, 2024. @article{Kopciuch2024, title = {Optimized optical tomography of quantum states of a room-temperature alkali-metal vapor}, author = {Marek Kopciuch and Magdalena Smolis and Adam Miranowicz and Szymon Pustelny}, url = {https://link.aps.org/doi/10.1103/PhysRevA.109.032402}, doi = {10.1103/PhysRevA.109.032402}, year = {2024}, date = {2024-03-01}, journal = {Phys. Rev. A}, volume = {109}, pages = {032402}, abstract = {We demonstrate an experimental technique for the quantum-state tomography of the collective qutrit states of a room-temperature alkali-metal vapor. It is based on the measurements of the polarization of light traversing the vapor subjected to a magnetic field. To assess the technique's robustness against errors, experimental investigations are supported with numerical simulations. This not only allows us to determine the fidelity of the reconstructed states, but also to analyze the quality of the reconstruction for specific experimental parameters, such as light tuning and the number of measurements. By utilizing the conditional number, we demonstrate that the reconstruction robustness can be optimized by a proper adjustment of experimental parameters, and further improvement is possible with the repetition of specific measurements. Our results demonstrate the potential of this high-fidelity reconstruction method of quantum states of room-temperature atomic vapors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We demonstrate an experimental technique for the quantum-state tomography of the collective qutrit states of a room-temperature alkali-metal vapor. It is based on the measurements of the polarization of light traversing the vapor subjected to a magnetic field. To assess the technique's robustness against errors, experimental investigations are supported with numerical simulations. This not only allows us to determine the fidelity of the reconstructed states, but also to analyze the quality of the reconstruction for specific experimental parameters, such as light tuning and the number of measurements. By utilizing the conditional number, we demonstrate that the reconstruction robustness can be optimized by a proper adjustment of experimental parameters, and further improvement is possible with the repetition of specific measurements. Our results demonstrate the potential of this high-fidelity reconstruction method of quantum states of room-temperature atomic vapors. |
| 225. | Krzysztof P. Wójcik, Tadeusz Domański, Ireneusz Weymann Signatures of Kondo-Majorana interplay in ac response Phys. Rev. B, 109 , pp. 075432, 2024. @article{Wójcik2024, title = {Signatures of Kondo-Majorana interplay in ac response}, author = {Krzysztof P. Wójcik and Tadeusz Domański and Ireneusz Weymann}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.109.075432}, doi = {10.1103/PhysRevB.109.075432}, year = {2024}, date = {2024-02-26}, journal = {Phys. Rev. B}, volume = {109}, pages = {075432}, abstract = {We analyze dynamical transport properties of a hybrid nanostructure, comprising a correlated quantum dot embedded between the source and drain electrodes, which are subject to an ac voltage, focusing on signatures imprinted on the charge transport by the side-attached Majorana zero-energy mode. The considerations are based on the Kubo formula, for which the relevant correlation functions are determined by using the numerical renormalization group approach, which allows us to consider the correlation effects due to the Coulomb repulsion and their interplay with the Majorana mode in a nonperturbative manner. We point out universal features of the dynamical conductance, showing up in the Kondo-Majorana regime, and differentiate them against the conventional Kondo and Majorana systems. In particular, we predict that the Majorana quasiparticles give rise to universal fractional values of the ac conductance in the well-defined frequency range below the peak at the Kondo scale. We also show this Kondo scale to actually increase with strengthening the coupling to the topological superconducting wire.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We analyze dynamical transport properties of a hybrid nanostructure, comprising a correlated quantum dot embedded between the source and drain electrodes, which are subject to an ac voltage, focusing on signatures imprinted on the charge transport by the side-attached Majorana zero-energy mode. The considerations are based on the Kubo formula, for which the relevant correlation functions are determined by using the numerical renormalization group approach, which allows us to consider the correlation effects due to the Coulomb repulsion and their interplay with the Majorana mode in a nonperturbative manner. We point out universal features of the dynamical conductance, showing up in the Kondo-Majorana regime, and differentiate them against the conventional Kondo and Majorana systems. In particular, we predict that the Majorana quasiparticles give rise to universal fractional values of the ac conductance in the well-defined frequency range below the peak at the Kondo scale. We also show this Kondo scale to actually increase with strengthening the coupling to the topological superconducting wire. |
| 224. | Viktoriia Drushliak, Konrad J. Kapcia, Marek Szafrański Journal of Materials Chemistry C, 12 (12), pp. 4360-4368, 2024. @article{Drushliak2024, title = {White-Light Emission Triggered by Pseudo Jahn-Teller Distortion at the Pressure-Induced Phase Transition in Cs4PbBr6}, author = {Viktoriia Drushliak and Konrad J. Kapcia and Marek Szafrański}, doi = {10.1039/D4TC00036F}, year = {2024}, date = {2024-02-20}, journal = {Journal of Materials Chemistry C}, volume = {12}, number = {12}, pages = {4360-4368}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 223. | Maciej Bąk Bound state attraction threshold in the layered Hubbard model Journal of Magnetism and Magnetic Materials, 592 , pp. 171756, 2024. @article{Bak2024, title = {Bound state attraction threshold in the layered Hubbard model}, author = {Maciej Bąk}, doi = {10.1016/j.jmmm.2024.171756}, year = {2024}, date = {2024-02-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {592}, pages = {171756}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 222. | Konrad J. Kapcia, Jan Barański Journal of Magnetism and Magnetic Materials, 591 , pp. 171702, 2024. @article{Kapcia2024c, title = {Magnetic and charge orders on the triangular lattice: Extended Hubbard model with intersite Ising-like magnetic interactions in the atomic limit}, author = {Konrad J. Kapcia and Jan Barański}, doi = {10.1016/j.jmmm.2023.171702}, year = {2024}, date = {2024-02-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {591}, pages = {171702}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 221. | Krzysztof Szulc, Yulia Kharlan, Pavlo Bondarenko, Elena V. Tartakovskaya, Maciej Krawczyk Impact of surface anisotropy on the spin-wave dynamics in a thin ferromagnetic film Phys. Rev. B, 109 , pp. 054430, 2024. @article{PhysRevB.109.054430, title = {Impact of surface anisotropy on the spin-wave dynamics in a thin ferromagnetic film}, author = {Krzysztof Szulc and Yulia Kharlan and Pavlo Bondarenko and Elena V. Tartakovskaya and Maciej Krawczyk}, url = {https://link.aps.org/doi/10.1103/PhysRevB.109.054430}, doi = {10.1103/PhysRevB.109.054430}, year = {2024}, date = {2024-02-01}, journal = {Phys. Rev. B}, volume = {109}, pages = {054430}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 220. | Andriy E. Serebryannikov, Ekmel Ozbay Scientific Reports, 14 (1), pp. 1580, 2024, ISSN: 2045-2322. @article{Serebryannikov2024, title = {Exploring localized ENZ resonances and their role in superscattering, wideband invisibility, and tunable scattering}, author = {Andriy E. Serebryannikov and Ekmel Ozbay}, url = {https://doi.org/10.1038/s41598-024-51503-y}, doi = {10.1038/s41598-024-51503-y}, issn = {2045-2322}, year = {2024}, date = {2024-01-18}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {1580}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 219. | Wojciech Rudziński, Józef Barnaś, Anna Dyrdał Spin waves in bilayers of transition metal dichalcogenides Physical Review B, 109 , pp. 035412, 2024. @article{Rudziński2024, title = {Spin waves in bilayers of transition metal dichalcogenides}, author = {Wojciech Rudziński and Józef Barnaś and Anna Dyrdał}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.109.035412}, doi = {10.1103/PhysRevB.109.035412}, year = {2024}, date = {2024-01-11}, journal = {Physical Review B}, volume = {109}, pages = {035412}, abstract = {Van der Waals magnetic materials are currently of great interest as materials for applications in future ultrathin nanoelectronics and nanospintronics. Due to weak coupling between individual monolayers, these materials can be easily obtained in the monolayer and bilayer forms. The latter are of specific interest as they may be considered as natural two-dimensional spin valves. In this paper, we theoretically study spin waves in bilayers of transition metal dichalcogenides. The considerations are carried within the general spin wave theory based on effective spin Hamiltonian and Holstein-Primakoff-Bogolubov transformation. The spin Hamiltonian includes intralayer as well as interlayer nearest-neighbor exchange interactions, easy-plane anisotropy, and additionally a weak in-plane easy-axis anisotropy. The bilayer systems consist of two ferromagnetic (in-plane magnetization) monolayers that are coupled either ferromagnetically or antiferromagnetically. In the latter case, we analyze the spin-wave spectra in all magnetic phases, i.e., in the antiferromagnetic, spin-flop, and ferromagnetic ones.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Van der Waals magnetic materials are currently of great interest as materials for applications in future ultrathin nanoelectronics and nanospintronics. Due to weak coupling between individual monolayers, these materials can be easily obtained in the monolayer and bilayer forms. The latter are of specific interest as they may be considered as natural two-dimensional spin valves. In this paper, we theoretically study spin waves in bilayers of transition metal dichalcogenides. The considerations are carried within the general spin wave theory based on effective spin Hamiltonian and Holstein-Primakoff-Bogolubov transformation. The spin Hamiltonian includes intralayer as well as interlayer nearest-neighbor exchange interactions, easy-plane anisotropy, and additionally a weak in-plane easy-axis anisotropy. The bilayer systems consist of two ferromagnetic (in-plane magnetization) monolayers that are coupled either ferromagnetically or antiferromagnetically. In the latter case, we analyze the spin-wave spectra in all magnetic phases, i.e., in the antiferromagnetic, spin-flop, and ferromagnetic ones. |
| 218. | Ye-Hong Chen, Yuan Qiu, Adam Miranowicz, Neill Lambert, Wei Qin, Roberto Stassi, Yan Xia, Shi-Biao Zheng, Franco Nori Sudden change of the photon output field marks phase transitions in the quantum Rabi model Communications Physics, 7 (5), 2024. @article{Chen2024, title = {Sudden change of the photon output field marks phase transitions in the quantum Rabi model}, author = {Ye-Hong Chen and Yuan Qiu and Adam Miranowicz and Neill Lambert and Wei Qin and Roberto Stassi and Yan Xia and Shi-Biao Zheng and Franco Nori}, url = {https://www.nature.com/articles/s42005-023-01457-w}, doi = {10.1038/s42005-023-01457-w}, year = {2024}, date = {2024-01-05}, journal = {Communications Physics}, volume = {7}, number = {5}, abstract = {The experimental observation of quantum phase transitions predicted by the quantum Rabi model in quantum critical systems is usually challenging due to the lack of signature experimental observables associated with them. Here, we describe a method to identify the dynamical critical phenomenon in the quantum Rabi model consisting of a three-level atom and a cavity at the quantum phase transition. Such a critical phenomenon manifests itself as a sudden change of steady-state output photons in the system driven by two classical fields, when both the atom and the cavity are initially unexcited. The process occurs as the high-frequency pump field is converted into the low-frequency Stokes field and multiple cavity photons in the normal phase, while this conversion cannot occur in the superradiant phase. The sudden change of steady-state output photons is an experimentally accessible measure to probe quantum phase transitions, as it does not require preparing the equilibrium state.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The experimental observation of quantum phase transitions predicted by the quantum Rabi model in quantum critical systems is usually challenging due to the lack of signature experimental observables associated with them. Here, we describe a method to identify the dynamical critical phenomenon in the quantum Rabi model consisting of a three-level atom and a cavity at the quantum phase transition. Such a critical phenomenon manifests itself as a sudden change of steady-state output photons in the system driven by two classical fields, when both the atom and the cavity are initially unexcited. The process occurs as the high-frequency pump field is converted into the low-frequency Stokes field and multiple cavity photons in the normal phase, while this conversion cannot occur in the superradiant phase. The sudden change of steady-state output photons is an experimentally accessible measure to probe quantum phase transitions, as it does not require preparing the equilibrium state. |
| 217. | Konrad J. Kapcia, V. Tkachenko, F. Capotondi, A. Lichtenstein, S. Molodtsov, P. Piekarz, B. Ziaja Scientific Reports, 14 , pp. 473, 2024. @article{Kapcia2024b, title = {Ultrafast demagnetization in bulk nickel induced by X-ray photons tuned to Ni M3 and L3 absorption edges}, author = {Konrad J. Kapcia and V. Tkachenko and F. Capotondi and A. Lichtenstein and S. Molodtsov and P. Piekarz and B. Ziaja}, doi = {10.1038/s41598-023-50467-9}, year = {2024}, date = {2024-01-04}, journal = {Scientific Reports}, volume = {14}, pages = {473}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 216. | Przemysław Chełminiak First-passage time statistics for non-linear diffusion Physica A, 633 , pp. 129370, 2024. @article{chełminiak_2024, title = {First-passage time statistics for non-linear diffusion}, author = {Przemysław Chełminiak}, year = {2024}, date = {2024-01-01}, journal = {Physica A}, volume = {633}, pages = {129370}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 215. | Sreedevi Janardhanan, Sławomir Mielcarek, Hubert Głowiński, Daniel Kiphart, Piotr Kuświk, Aleksandra Trzaskowska Spin wave dynamics in CoFeB bilayers with wedged Au spacer Journal of Magnetism and Magnetic Materials, 589 , pp. 171570, 2024, ISSN: 0304-8853. @article{JANARDHANAN2024171570, title = {Spin wave dynamics in CoFeB bilayers with wedged Au spacer}, author = {Sreedevi Janardhanan and Sławomir Mielcarek and Hubert Głowiński and Daniel Kiphart and Piotr Kuświk and Aleksandra Trzaskowska}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323012209}, doi = {https://doi.org/10.1016/j.jmmm.2023.171570}, issn = {0304-8853}, year = {2024}, date = {2024-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {589}, pages = {171570}, abstract = {This paper presents the experimental studies of ferromagnetic layers separated by a heavy metal wedge. The studied system consists of two thin layers of CoFeB separated by a wedged Au spacer. By performing Brillouin light scattering measurements of the spin-wave dispersion relations, and dependences on the magnetic field, we extract magnetic parameters in the studied ferromagnetic layers as a function of heavy metal thickness. We concluded that for thin ferromagnetic double layers, the magnetic properties strongly depend on the thickness of the wedge gold layer spacer. In particular, the presence of perpendicular magnetic anisotropy diminishes as the thickness of the magnetic material is increased, and at the spacers thicker than 2.5 nm the dynamic coupling between propagating spin waves in both layers is negligible. These findings have potential advantages for the development of future spintronic devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents the experimental studies of ferromagnetic layers separated by a heavy metal wedge. The studied system consists of two thin layers of CoFeB separated by a wedged Au spacer. By performing Brillouin light scattering measurements of the spin-wave dispersion relations, and dependences on the magnetic field, we extract magnetic parameters in the studied ferromagnetic layers as a function of heavy metal thickness. We concluded that for thin ferromagnetic double layers, the magnetic properties strongly depend on the thickness of the wedge gold layer spacer. In particular, the presence of perpendicular magnetic anisotropy diminishes as the thickness of the magnetic material is increased, and at the spacers thicker than 2.5 nm the dynamic coupling between propagating spin waves in both layers is negligible. These findings have potential advantages for the development of future spintronic devices. |
| 214. | Agnieszka Cichy, Konrad J. Kapcia, Andrzej Ptok J. Magn. Magn. Mater., 589 , pp. 171522, 2024. @article{Cichy2024, title = {Spin-polarized superconducting phase in semiconducting system with next-nearest-neighbor hopping on the honeycomb lattice}, author = {Agnieszka Cichy and Konrad J. Kapcia and Andrzej Ptok}, doi = {10.1016/j.jmmm.2023.171522}, year = {2024}, date = {2024-01-01}, journal = {J. Magn. Magn. Mater.}, volume = {589}, pages = {171522}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 213. | Konrad J. Kapcia, V. Lipp, V. Tkachenko, B. Ziaja Comprehensive Computational Chemistry (First Edition), 3 , pp. 858-864, 2024. @article{Kapcia2024, title = {Theoretical analysis of X-Ray Free-Electron-Laser Experimental Data Using Monte-Carlo and Molecular-Dynamics Based Computational Tools}, author = {Konrad J. Kapcia and V. Lipp and V. Tkachenko and B. Ziaja}, doi = {10.1016/B978-0-12-821978-2.00110-0}, year = {2024}, date = {2024-01-01}, journal = {Comprehensive Computational Chemistry (First Edition)}, volume = {3}, pages = {858-864}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 212. | Josef Kadlec, Karol Bartkiewicz, Antonín Černoch, Karel Lemr, Adam Miranowicz Opt. Express, 32 (2), pp. 2333–2346, 2024. @article{Kadlec:24, title = {Experimental hierarchy of the nonclassicality of single-qubit states via potentials for entanglement, steering, and Bell nonlocality}, author = {Josef Kadlec and Karol Bartkiewicz and Antonín Černoch and Karel Lemr and Adam Miranowicz}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-32-2-2333}, doi = {10.1364/OE.506169}, year = {2024}, date = {2024-01-01}, journal = {Opt. Express}, volume = {32}, number = {2}, pages = {2333--2346}, publisher = {Optica Publishing Group}, abstract = {Entanglement potentials are a promising way to quantify the nonclassicality of single-mode states. They are defined by the amount of entanglement (expressed by, e.g., the Wootters concurrence) obtained after mixing the examined single-mode state with a purely classical state; such as the vacuum or a coherent state. We generalize the idea of entanglement potentials to other quantum correlations: the EPR steering and Bell nonlocality, thus enabling us to study mutual hierarchies of these nonclassicality potentials. Instead of the usual vacuum and one-photon superposition states, we experimentally test this concept using specially tailored polarization-encoded single-photon states. One polarization encodes a given nonclassical single-mode state, while the other serves as the vacuum place-holder. This technique proves to be experimentally more convenient in comparison to the vacuum and a one-photon superposition as it does not require the vacuum detection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Entanglement potentials are a promising way to quantify the nonclassicality of single-mode states. They are defined by the amount of entanglement (expressed by, e.g., the Wootters concurrence) obtained after mixing the examined single-mode state with a purely classical state; such as the vacuum or a coherent state. We generalize the idea of entanglement potentials to other quantum correlations: the EPR steering and Bell nonlocality, thus enabling us to study mutual hierarchies of these nonclassicality potentials. Instead of the usual vacuum and one-photon superposition states, we experimentally test this concept using specially tailored polarization-encoded single-photon states. One polarization encodes a given nonclassical single-mode state, while the other serves as the vacuum place-holder. This technique proves to be experimentally more convenient in comparison to the vacuum and a one-photon superposition as it does not require the vacuum detection. |
| 211. | Anna Krzyżewska, Anna Dyrdał Bilinear magnetoresistance in 2DEG with isotropic cubic Rashba spin–orbit interaction Journal of Magnetism and Magnetic Materials, 589 , pp. 171615, 2024. @article{Krzyżewska2024, title = {Bilinear magnetoresistance in 2DEG with isotropic cubic Rashba spin–orbit interaction}, author = {Anna Krzyżewska and Anna Dyrdał}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323012659?via%3Dihub}, doi = {10.1016/j.jmmm.2023.171615}, year = {2024}, date = {2024-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {589}, pages = {171615}, abstract = {Bilinear magnetoresistance has been studied theoretically in 2D systems with isotropic cubic form of Rashba spin–orbit interaction. We have derived the effective spin–orbital field due to current-induced spin polarization and discussed its contribution to the unidirectional system response. The analyzed model can be applied to the semiconductor quantum wells as well as 2DEG at the surfaces and interfaces of perovskite oxides.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Bilinear magnetoresistance has been studied theoretically in 2D systems with isotropic cubic form of Rashba spin–orbit interaction. We have derived the effective spin–orbital field due to current-induced spin polarization and discussed its contribution to the unidirectional system response. The analyzed model can be applied to the semiconductor quantum wells as well as 2DEG at the surfaces and interfaces of perovskite oxides. |
| 210. | Mirali Jafari, Anna Dyrdał Journal of Magnetism and Magnetic Materials, 589 , pp. 171618, 2024. @article{Jafari2024, title = {Effect of strain on the electronic and magnetic properties of bilayer T-phase VS2 : A first-principles study}, author = {Mirali Jafari and Anna Dyrdał}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323012684?via%3Dihub}, doi = {10.1016/j.jmmm.2023.171618}, year = {2024}, date = {2024-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {589}, pages = {171618}, abstract = {Using the Density Functional Theory (DFT) calculations, we determined the electronic and magnetic properties of a T-phase VS2 bilayer as a function of tensile and compressive strain. First, we determine the ground state structural parameters and then the band structure, magnetic anisotropy, exchange parameters, and Curie temperature. Variation of these parameters with the strain is carefully analyzed and described. The easy-plane anisotropy, which is rather small in the absence of strain, becomes remarkably enhanced by tensile strain and reduced almost to zero by compressive strain. We also show that the exchange parameters and the Curie temperature are remarkably reduced for the compressive strains below roughly −4%. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Using the Density Functional Theory (DFT) calculations, we determined the electronic and magnetic properties of a T-phase VS2 bilayer as a function of tensile and compressive strain. First, we determine the ground state structural parameters and then the band structure, magnetic anisotropy, exchange parameters, and Curie temperature. Variation of these parameters with the strain is carefully analyzed and described. The easy-plane anisotropy, which is rather small in the absence of strain, becomes remarkably enhanced by tensile strain and reduced almost to zero by compressive strain. We also show that the exchange parameters and the Curie temperature are remarkably reduced for the compressive strains below roughly −4%. |
| 209. | Amir Zarezad, Józef Barnaś, Anna Dyrdał, Alireza Qaiumzadeh Skyrmion-deriven topological spin and charge Hall effects in diffusive antiferromagnetic thin films Journal of Magnetism and Magnetic Materials, 589 , pp. 171599, 2024. @article{Zarezad2024, title = {Skyrmion-deriven topological spin and charge Hall effects in diffusive antiferromagnetic thin films}, author = {Amir Zarezad and Józef Barnaś and Anna Dyrdał and Alireza Qaiumzadeh}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323012490?via%3Dihub}, doi = {10.1016/j.jmmm.2023.171599}, year = {2024}, date = {2024-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {589}, pages = { 171599}, abstract = {We investigate topological Hall effects in a metallic antiferromagnetic (AFM) thin film and/or at the interface of an AFM insulator–normal metal bilayer with a single skyrmion in the diffusive regime. To determine the spin- and charge Hall currents, we employed a Boltzmann kinetic equation with both spin-dependent and spin-flip scatterings. The interaction between conduction electrons and static skyrmions is included in the Boltzmann equation via the corresponding emergent magnetic field arising from the skyrmion texture. We compute intrinsic and extrinsic contributions to the topological spin Hall effect and spin accumulation, induced by an AFM skyrmion. We show that although the spin Hall current vanishes rapidly outside the skyrmion, the spin accumulation can be finite at the edges far from the skyrmion, provided the spin diffusion length is longer than the skyrmion radius. In addition, We show that in the presence of a spin-dependent relaxation time, the topological charge Hall effect is finite and we determine the corresponding Hall voltage. Our results may help to explore antiferromagnetic skyrmions by electrical means in real materials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate topological Hall effects in a metallic antiferromagnetic (AFM) thin film and/or at the interface of an AFM insulator–normal metal bilayer with a single skyrmion in the diffusive regime. To determine the spin- and charge Hall currents, we employed a Boltzmann kinetic equation with both spin-dependent and spin-flip scatterings. The interaction between conduction electrons and static skyrmions is included in the Boltzmann equation via the corresponding emergent magnetic field arising from the skyrmion texture. We compute intrinsic and extrinsic contributions to the topological spin Hall effect and spin accumulation, induced by an AFM skyrmion. We show that although the spin Hall current vanishes rapidly outside the skyrmion, the spin accumulation can be finite at the edges far from the skyrmion, provided the spin diffusion length is longer than the skyrmion radius. In addition, We show that in the presence of a spin-dependent relaxation time, the topological charge Hall effect is finite and we determine the corresponding Hall voltage. Our results may help to explore antiferromagnetic skyrmions by electrical means in real materials. |
| 208. | Emil Siuda, Piotr Trocha Thermal generation of spin current in a quantum dot coupled to magnetic insulators Journal of Magnetism and Magnetic Materials, 589 , pp. 171495, 2024. @article{Siuda2024, title = {Thermal generation of spin current in a quantum dot coupled to magnetic insulators}, author = {Emil Siuda and Piotr Trocha}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323011459}, doi = {/10.1016/j.jmmm.2023.171495}, year = {2024}, date = {2024-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {589}, pages = {171495}, abstract = {In this work, we study thermally-generated spin current in the system consisting of a quantum dot connected to two magnetic insulators. The external leads are kept at different temperatures which leads to an imbalance of magnon populations in two magnetic insulators resulting in the flow of the magnon (spin) current. We take into account many-body magnon interactions and incorporate energy-dependent density of states of the magnetic insulators. Both features can strongly affect magnon distribution in the magnetic insulators and the coupling strengths between the leads and the dot, and thus, the thermally generated spin current. All the calculations are carried out in the weak coupling regime. We show, that results obtained with a density of states being a function of energy differ significantly from the ones obtained with a density of states taken as a constant. In turn, magnon interactions in the leads proved to be important at high temperatures and large values of energy of transported spin waves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work, we study thermally-generated spin current in the system consisting of a quantum dot connected to two magnetic insulators. The external leads are kept at different temperatures which leads to an imbalance of magnon populations in two magnetic insulators resulting in the flow of the magnon (spin) current. We take into account many-body magnon interactions and incorporate energy-dependent density of states of the magnetic insulators. Both features can strongly affect magnon distribution in the magnetic insulators and the coupling strengths between the leads and the dot, and thus, the thermally generated spin current. All the calculations are carried out in the weak coupling regime. We show, that results obtained with a density of states being a function of energy differ significantly from the ones obtained with a density of states taken as a constant. In turn, magnon interactions in the leads proved to be important at high temperatures and large values of energy of transported spin waves. |
| 207. | Jan Roik, Karol Bartkiewicz, Antonín Černoch, Karel Lemr Routing in quantum communication networks using reinforcement machine learning Quantum Information Processing, 23 (3), 2024, ISSN: 1573-1332. @article{Roik2024, title = {Routing in quantum communication networks using reinforcement machine learning}, author = {Jan Roik and Karol Bartkiewicz and Antonín Černoch and Karel Lemr}, url = {http://dx.doi.org/10.1007/s11128-024-04287-z}, doi = {10.1007/s11128-024-04287-z}, issn = {1573-1332}, year = {2024}, date = {2024-01-01}, journal = {Quantum Information Processing}, volume = {23}, number = {3}, publisher = {Springer Science and Business Media LLC}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 206. | Jolanta Natalia Latosińska, Magdalena Latosińska, Janez Seliger, Veselko Žagar, Tomaž Apih Pharmaceuticals, 17 (4), 2024, ISSN: 1424-8247. @article{ph17040445, title = {Butterfly Effect in Cytarabine: Combined NMR-NQR Experiment, Solid-State Computational Modeling, Quantitative Structure-Property Relationships and Molecular Docking Study}, author = {Jolanta Natalia Latosińska and Magdalena Latosińska and Janez Seliger and Veselko Žagar and Tomaž Apih}, url = {https://www.mdpi.com/1424-8247/17/4/445}, doi = {10.3390/ph17040445}, issn = {1424-8247}, year = {2024}, date = {2024-01-01}, journal = {Pharmaceuticals}, volume = {17}, number = {4}, abstract = {Cytarabine (Ara-C) is a synthetic isomer of cytidine that differs from cytidine and deoxycytidine only in the sugar. The use of arabinose instead of deoxyribose hinders the formation of phosphodiester linkages between pentoses, preventing the DNA chain from elongation and interrupting the DNA synthesis. The minor structural alteration (the inversion of hydroxyl at the 2′ positions of the sugar) leads to change of the biological activity from anti-depressant and DNA/RNA block builder to powerful anti-cancer. Our study aimed to determine the molecular nature of this phenomenon. Three 1H-14N NMR-NQR experimental techniques, followed by solid-state computational modelling (Quantum Theory of Atoms in Molecules, Reduced Density Gradient and 3D Hirshfeld surfaces), Quantitative Structure–Property Relationships, Spackman’s Hirshfeld surfaces and Molecular Docking were used. Multifaceted analysis—combining experiments, computational modeling and molecular docking—provides deep insight into three-dimensional packing at the atomic and molecular levels, but is challenging. A spectrum with nine lines indicating the existence of three chemically inequivalent nitrogen sites in the Ara-C molecule was recorded, and the lines were assigned to them. The influence of the structural alteration on the NQR parameters was modeled in the solid (GGA/RPBE). For the comprehensive description of the nature of these interactions several factors were considered, including relative reactivity and the involvement of heavy atoms in various non-covalent interactions. The binding modes in the solid state and complex with dCK were investigated using the novel approaches: radial plots, heatmaps and root-mean-square deviation of the binding mode. We identified the intramolecular OH···O hydrogen bond as the key factor responsible for forcing the glycone conformation and strengthening NH···O bonds with Gln97, Asp133 and Ara128, and stacking with Phe137. The titular butterfly effect is associated with both the inversion and the presence of this intramolecular hydrogen bond. Our study elucidates the differences in the binding modes of Ara-C and cytidine, which should guide the design of more potent anti-cancer and anti-viral analogues.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cytarabine (Ara-C) is a synthetic isomer of cytidine that differs from cytidine and deoxycytidine only in the sugar. The use of arabinose instead of deoxyribose hinders the formation of phosphodiester linkages between pentoses, preventing the DNA chain from elongation and interrupting the DNA synthesis. The minor structural alteration (the inversion of hydroxyl at the 2′ positions of the sugar) leads to change of the biological activity from anti-depressant and DNA/RNA block builder to powerful anti-cancer. Our study aimed to determine the molecular nature of this phenomenon. Three 1H-14N NMR-NQR experimental techniques, followed by solid-state computational modelling (Quantum Theory of Atoms in Molecules, Reduced Density Gradient and 3D Hirshfeld surfaces), Quantitative Structure–Property Relationships, Spackman’s Hirshfeld surfaces and Molecular Docking were used. Multifaceted analysis—combining experiments, computational modeling and molecular docking—provides deep insight into three-dimensional packing at the atomic and molecular levels, but is challenging. A spectrum with nine lines indicating the existence of three chemically inequivalent nitrogen sites in the Ara-C molecule was recorded, and the lines were assigned to them. The influence of the structural alteration on the NQR parameters was modeled in the solid (GGA/RPBE). For the comprehensive description of the nature of these interactions several factors were considered, including relative reactivity and the involvement of heavy atoms in various non-covalent interactions. The binding modes in the solid state and complex with dCK were investigated using the novel approaches: radial plots, heatmaps and root-mean-square deviation of the binding mode. We identified the intramolecular OH···O hydrogen bond as the key factor responsible for forcing the glycone conformation and strengthening NH···O bonds with Gln97, Asp133 and Ara128, and stacking with Phe137. The titular butterfly effect is associated with both the inversion and the presence of this intramolecular hydrogen bond. Our study elucidates the differences in the binding modes of Ara-C and cytidine, which should guide the design of more potent anti-cancer and anti-viral analogues. |
| 205. | Magdalena Latosińska, Jolanta Natalia Latosińska Molecules, 29 (2), pp. 441, 2024, ISSN: 1420-3049. @article{Latosiska2024, title = {Favipiravir Analogues as Inhibitors of SARS-CoV-2 RNA-Dependent RNA Polymerase, Combined Quantum Chemical Modeling, Quantitative Structure–Property Relationship, and Molecular Docking Study}, author = {Magdalena Latosińska and Jolanta Natalia Latosińska}, url = {http://dx.doi.org/10.3390/molecules29020441}, doi = {10.3390/molecules29020441}, issn = {1420-3049}, year = {2024}, date = {2024-01-01}, journal = {Molecules}, volume = {29}, number = {2}, pages = {441}, publisher = {MDPI AG}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 204. | E S Hevorkian, V P Nerubatskyi, R V Vovk, T Szumiata, Jolanta Natalia Latosińska Foamy ceramic filters and new possibilities of their applications Ceramics International, 50 (4), pp. 6961–6968, 2024, ISSN: 0272-8842. @article{Hevorkian2024b, title = {Foamy ceramic filters and new possibilities of their applications}, author = {E S Hevorkian and V P Nerubatskyi and R V Vovk and T Szumiata and Jolanta Natalia Latosińska}, url = {http://dx.doi.org/10.1016/j.ceramint.2023.12.046}, doi = {10.1016/j.ceramint.2023.12.046}, issn = {0272-8842}, year = {2024}, date = {2024-01-01}, journal = {Ceramics International}, volume = {50}, number = {4}, pages = {6961–6968}, publisher = {Elsevier BV}, keywords = {}, pubstate = {published}, tppubtype = {article} } |