List of publications
Department of Mesoscopic Physics
Department of Quantum Information
Department of Physics of Nanostructures
Department of Theory of Condensed Matter
2025 |
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| 322. | Csanád Hajdú, Cătălin Paşcu Moca, Balázs Dóra, Ireneusz Weymann, Gergely Zaránd Kondo compensation in a pseudogap phase: A renormalization group study Phys. Rev. B, 111 , pp. 155125, 2025. @article{Hajdú2025, title = {Kondo compensation in a pseudogap phase: A renormalization group study}, author = {Csanád Hajdú and Cătălin Paşcu Moca and Balázs Dóra and Ireneusz Weymann and Gergely Zaránd}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.111.155125}, doi = {10.1103/PhysRevB.111.155125}, year = {2025}, date = {2025-04-15}, journal = {Phys. Rev. B}, volume = {111}, pages = {155125}, abstract = {We investigate the critical behavior of the Kondo compensation in the presence of a power-law pseudogap in the density of states, 𝜌(𝜔)∼|𝜔|𝜀. For 𝜀<1, generically—in the absence of particle-hole symmetry—this model exhibits a quantum phase transition from a partially screened doublet ground state to a fully screened many-body ground state upon increasing the exchange coupling 𝑗. At the critical point 𝑗c, the Kondo compensation is found to scale as 𝜅(𝑗<𝑗c)=1−𝑔(𝑗) with the local 𝑔-factor vanishing as 𝑔∼|𝑗−𝑗c|^𝛽. We combine the perturbative drone fermion method with the nonperturbative numerical renormalization group computations to determine the critical exponent 𝛽(𝜀), which exhibits a nonmonotonous behavior as a function of 𝜀. Our results confirm that the Kondo cloud builds up continuously in the presence of a weak pseudogap as one approaches the phase transition.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate the critical behavior of the Kondo compensation in the presence of a power-law pseudogap in the density of states, 𝜌(𝜔)∼|𝜔|𝜀. For 𝜀<1, generically—in the absence of particle-hole symmetry—this model exhibits a quantum phase transition from a partially screened doublet ground state to a fully screened many-body ground state upon increasing the exchange coupling 𝑗. At the critical point 𝑗c, the Kondo compensation is found to scale as 𝜅(𝑗<𝑗c)=1−𝑔(𝑗) with the local 𝑔-factor vanishing as 𝑔∼|𝑗−𝑗c|^𝛽. We combine the perturbative drone fermion method with the nonperturbative numerical renormalization group computations to determine the critical exponent 𝛽(𝜀), which exhibits a nonmonotonous behavior as a function of 𝜀. Our results confirm that the Kondo cloud builds up continuously in the presence of a weak pseudogap as one approaches the phase transition. |
| 321. | Ichiro Inoue, Taito Osaka, Victor Tkachenko, Toru Hara, Konrad J. Kapcia, Yuichi Inubushi, Shogo Kawaguchi, Jumpei Yamada, Eiji Nishibori, Makina Yabashi, Beata Ziaja High-intensity X-ray pump-monochromatic X-ray probe technique across time zero Optica, 12 (4), pp. 530-533, 2025, ISSN: 2334-2536. @article{Inoue2025, title = {High-intensity X-ray pump-monochromatic X-ray probe technique across time zero}, author = {Ichiro Inoue and Taito Osaka and Victor Tkachenko and Toru Hara and Konrad J. Kapcia and Yuichi Inubushi and Shogo Kawaguchi and Jumpei Yamada and Eiji Nishibori and Makina Yabashi and Beata Ziaja}, doi = {10.1364/OPTICA.555433}, issn = {2334-2536}, year = {2025}, date = {2025-04-15}, journal = {Optica}, volume = {12}, number = {4}, pages = {530-533}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 320. | O. M. Baksalary, D. Bernstein The Rao-Mitra-Bhimasankaram relation is strongly antisymmetric Linear Algebra and its Applications, 710 , pp. 80-94, 2025. @article{Baksalary2025, title = {The Rao-Mitra-Bhimasankaram relation is strongly antisymmetric}, author = {O. M. Baksalary and D. Bernstein}, doi = {10.1016/j.laa.2025.01.029}, year = {2025}, date = {2025-04-01}, journal = {Linear Algebra and its Applications}, volume = {710}, pages = {80-94}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 319. | Jian Tang, Yunlan Zuo, Xun-Wei Xu, Ran Huang, Adam Miranowicz, Franco Nori, Hui Jing Achieving Robust Single-Photon Blockade with a Single Nanotip Nano Letters, 25 (12), pp. 4705-4712, 2025, ISSN: 1530-6984. @article{Tang2025, title = {Achieving Robust Single-Photon Blockade with a Single Nanotip}, author = {Jian Tang and Yunlan Zuo and Xun-Wei Xu and Ran Huang and Adam Miranowicz and Franco Nori and Hui Jing}, url = {https://doi.org/10.1021/acs.nanolett.4c05433}, doi = {10.1021/acs.nanolett.4c05433}, issn = {1530-6984}, year = {2025}, date = {2025-03-26}, journal = {Nano Letters}, volume = {25}, number = {12}, pages = {4705-4712}, publisher = {American Chemical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 318. | Andriy E. Serebryannikov, Atilla O Cakmak, Evrim Colak Scientific Reports, 15 (1), pp. 7873, 2025, ISSN: 2045-2322. @article{Serebryannikov2025, title = {Effects of gradual deformation of identical and nonidentical, rotated and nonrotated U-shaped subwavelength resonators in few-layer metasurfaces}, author = {Andriy E. Serebryannikov and Atilla O Cakmak and Evrim Colak}, url = {https://doi.org/10.1038/s41598-025-88678-x}, doi = {10.1038/s41598-025-88678-x}, issn = {2045-2322}, year = {2025}, date = {2025-03-06}, journal = {Scientific Reports}, volume = {15}, number = {1}, pages = {7873}, abstract = {Raising of negative-index medium has been going hand-by-hand with the exploration of quasiplanar subwavelength resonators. Now they are widely used in modern microwave, terahertz, and infrared devices, as well as in advanced physics research. Effects of stacking of the arrays of subwavelength resonators in one few-layer metasurface is connected with the key problems of modern electrical engineering, applied physics, and beyond. Recently, the interest to subwavelength resonators has been growing due to the progress in topological photonics and non-Hermitian photonics. In this paper, the selected effects of arrays coupling in a few-layer metasurface are revisited with yet uncommon focus, i.e., survival and (dis)appearance of subwavelength resonances at the gradual deformation of the resonators at a given lattice period. Microwave frequency range has been chosen to illustrate the concept. The case when the metasurfaces comprise two periodically placed U-shaped resonator arrays is considered. The sizes of the resonators are either varied simultaneously for both front-side and back-side arrays or for the back-side array only. The main purpose of this study is to explore the basic scenarios of resonance evolution in the space of geometrical parameters. It is shown that different resonances may be sensitive to the variations in geometrical parameters and to the dissimilarity between the front-side and back-side arrays to a different extent. The obtained results point to the existence of the bands, resonances, polarization-conversion and related asymmetric transmission regimes that are robust to the deformations. They can serve as the starting point in understanding the functional capability of the physical features while adjusting the size for a much wider variety of the types of subwavelength resonators. Their unveiling promises a wide avenue towards the realization of new frequency-domain and angle-domain filters, ultrathin polarization-plane convertors, asymmetric transmission devices and advanced microwave antennas.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Raising of negative-index medium has been going hand-by-hand with the exploration of quasiplanar subwavelength resonators. Now they are widely used in modern microwave, terahertz, and infrared devices, as well as in advanced physics research. Effects of stacking of the arrays of subwavelength resonators in one few-layer metasurface is connected with the key problems of modern electrical engineering, applied physics, and beyond. Recently, the interest to subwavelength resonators has been growing due to the progress in topological photonics and non-Hermitian photonics. In this paper, the selected effects of arrays coupling in a few-layer metasurface are revisited with yet uncommon focus, i.e., survival and (dis)appearance of subwavelength resonances at the gradual deformation of the resonators at a given lattice period. Microwave frequency range has been chosen to illustrate the concept. The case when the metasurfaces comprise two periodically placed U-shaped resonator arrays is considered. The sizes of the resonators are either varied simultaneously for both front-side and back-side arrays or for the back-side array only. The main purpose of this study is to explore the basic scenarios of resonance evolution in the space of geometrical parameters. It is shown that different resonances may be sensitive to the variations in geometrical parameters and to the dissimilarity between the front-side and back-side arrays to a different extent. The obtained results point to the existence of the bands, resonances, polarization-conversion and related asymmetric transmission regimes that are robust to the deformations. They can serve as the starting point in understanding the functional capability of the physical features while adjusting the size for a much wider variety of the types of subwavelength resonators. Their unveiling promises a wide avenue towards the realization of new frequency-domain and angle-domain filters, ultrathin polarization-plane convertors, asymmetric transmission devices and advanced microwave antennas. |
| 317. | Arpan Roy, Arnab Laha, Abhijit Biswas, Bishnu P Pal, Somnath Ghosh, Adam Miranowicz Dynamically encircled higher-order exceptional points in an optical fiber Physica Scripta, 100 (4), pp. 045529, 2025. @article{Roy2025, title = {Dynamically encircled higher-order exceptional points in an optical fiber}, author = {Arpan Roy and Arnab Laha and Abhijit Biswas and Bishnu P Pal and Somnath Ghosh and Adam Miranowicz}, url = {https://dx.doi.org/10.1088/1402-4896/adbea6}, doi = {10.1088/1402-4896/adbea6}, year = {2025}, date = {2025-03-01}, journal = {Physica Scripta}, volume = {100}, number = {4}, pages = {045529}, publisher = {IOP Publishing}, abstract = {The unique properties of exceptional point (EP) singularities, arising from non-Hermitian physics, have unlocked new possibilities for manipulating lightmatter interactions. A tailored gain-loss variation, while encircling higher-order EPs dynamically, can significantly enhance the control of the topological flow of light in multi-level photonic systems. In particular, the integration of dynamically encircled higher-order EPs within fiber geometries holds great promise for advancing specialty optical fiber applications, though a research gap remains in exploring and realizing such configurations. Here, we report a triple-core specialty optical fiber engineered with customized loss and gain to explore the topological characteristics of a third-order EP (EP3), formed by two interconnected second-order EPs (EP2s). We elucidate chiral and nonchiral light transmission through the fiber, based on second- and third-order branch point behaviors and associated adiabatic and nonadiabatic modal characteristics, while considering various dynamical parametric loops to encircle the embedded EPs. We investigate the persistence of EP-induced light dynamics specifically in the parametric regions immediately adjacent to, though not encircling, the embedded EPs, thereby potentially leading to improved device performance. Our findings offer significant implications for the design and implementation of novel light management technologies in all-fiber photonics and communications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The unique properties of exceptional point (EP) singularities, arising from non-Hermitian physics, have unlocked new possibilities for manipulating lightmatter interactions. A tailored gain-loss variation, while encircling higher-order EPs dynamically, can significantly enhance the control of the topological flow of light in multi-level photonic systems. In particular, the integration of dynamically encircled higher-order EPs within fiber geometries holds great promise for advancing specialty optical fiber applications, though a research gap remains in exploring and realizing such configurations. Here, we report a triple-core specialty optical fiber engineered with customized loss and gain to explore the topological characteristics of a third-order EP (EP3), formed by two interconnected second-order EPs (EP2s). We elucidate chiral and nonchiral light transmission through the fiber, based on second- and third-order branch point behaviors and associated adiabatic and nonadiabatic modal characteristics, while considering various dynamical parametric loops to encircle the embedded EPs. We investigate the persistence of EP-induced light dynamics specifically in the parametric regions immediately adjacent to, though not encircling, the embedded EPs, thereby potentially leading to improved device performance. Our findings offer significant implications for the design and implementation of novel light management technologies in all-fiber photonics and communications. |
| 316. | Syamlal Sankaran Kunnath, Mateusz Zelent, Mathieu Moalic, Maciej Krawczyk Small Structures, n/a (n/a), pp. 2400627, 2025. @article{https://doi.org/10.1002/sstr.202400627, title = {Enhancement of Dynamical Coupling in Artificial Spin-Ice Systems by Incorporating Perpendicularly Magnetized Ferromagnetic Matrix}, author = {Syamlal Sankaran Kunnath and Mateusz Zelent and Mathieu Moalic and Maciej Krawczyk}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sstr.202400627}, doi = {https://doi.org/10.1002/sstr.202400627}, year = {2025}, date = {2025-02-19}, journal = {Small Structures}, volume = {n/a}, number = {n/a}, pages = {2400627}, abstract = {Artificial spin-ice (ASI) systems, consisting of arrays of interacting ferromagnetic nanoelements, offer a versatile platform for reconfigurable magnonics with potential in GHz logic and neuromorphic computing. However, weak dipolar coupling between nanoelements severely limits their functionality. A rich spin-wave spectrum is numerically demonstrated in an ASI structure immersed in a perpendicularly magnetized ferromagnetic matrix, which is different from a conventional ASI system. A strong magnon–magnon coupling is observed between the bulk second-order mode of the ASI and the fundamental mode of the matrix, supported by a pronounced anticrossing frequency gap. It is shown that, in addition to the internanoelement dipolar coupling, exchange interactions at the nanoelement-matrix interface play a crucial role in this hybridization. Furthermore, the strength of the coupling can be enhanced by almost 40% just by reconfiguring the magnetization at the vertices from low-energy to high-energy monopole states. These results open the way to exploit ASI systems for magnonic applications, taking advantage of the strong coupling and vertex-dependent dynamics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Artificial spin-ice (ASI) systems, consisting of arrays of interacting ferromagnetic nanoelements, offer a versatile platform for reconfigurable magnonics with potential in GHz logic and neuromorphic computing. However, weak dipolar coupling between nanoelements severely limits their functionality. A rich spin-wave spectrum is numerically demonstrated in an ASI structure immersed in a perpendicularly magnetized ferromagnetic matrix, which is different from a conventional ASI system. A strong magnon–magnon coupling is observed between the bulk second-order mode of the ASI and the fundamental mode of the matrix, supported by a pronounced anticrossing frequency gap. It is shown that, in addition to the internanoelement dipolar coupling, exchange interactions at the nanoelement-matrix interface play a crucial role in this hybridization. Furthermore, the strength of the coupling can be enhanced by almost 40% just by reconfiguring the magnetization at the vertices from low-energy to high-energy monopole states. These results open the way to exploit ASI systems for magnonic applications, taking advantage of the strong coupling and vertex-dependent dynamics. |
| 315. | Krzysztof Sobucki, Igor Lyubchanskii, Maciej Krawczyk, Paweł Gruszecki Goos-Hänchen shift of inelastically scattered spin-wave beams and cascade nonlinear magnon processes Scientific Reports, 15 (1), pp. 5538, 2025, ISSN: 2045-2322. @article{Sobucki2025, title = {Goos-Hänchen shift of inelastically scattered spin-wave beams and cascade nonlinear magnon processes}, author = {Krzysztof Sobucki and Igor Lyubchanskii and Maciej Krawczyk and Paweł Gruszecki}, url = {https://doi.org/10.1038/s41598-025-86879-y}, doi = {10.1038/s41598-025-86879-y}, issn = {2045-2322}, year = {2025}, date = {2025-02-14}, journal = {Scientific Reports}, volume = {15}, number = {1}, pages = {5538}, abstract = {We study, using micromagnetic simulations, the inelastic scattering of spin-wave beams on edge-localized spin-wave modes in a thin ferromagnetic film. In the splitting and confluence processes, the new spin-wave beams are generated with frequencies shifted by the edge-mode frequency. We report that inelastically scattered spin-wave beams in both processes not only change their direction of propagation but also undergo lateral shifts along the interface, analogous to the Goos--Hänchen effect known in optics. These shifts of inelastically scattered beams, for a few special cases described in the paper, can be in the range of several wavelengths, which is larger than the Goos--Hänchen shift of elastically reflected beam. Unexpectedly, at selected frequencies, we found a significant increase in the value of the lateral shifts of the scattered spin-wave beams formed in the confluence process. We show that this effect is associated with the cascading nonlinear processes taking place at the edge of the film and involving the primary edge spin wave. Our results make an important contribution to the understanding of the nonlinear nature of spin waves and provide a way to exploit it in signal processing with magnons.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We study, using micromagnetic simulations, the inelastic scattering of spin-wave beams on edge-localized spin-wave modes in a thin ferromagnetic film. In the splitting and confluence processes, the new spin-wave beams are generated with frequencies shifted by the edge-mode frequency. We report that inelastically scattered spin-wave beams in both processes not only change their direction of propagation but also undergo lateral shifts along the interface, analogous to the Goos--Hänchen effect known in optics. These shifts of inelastically scattered beams, for a few special cases described in the paper, can be in the range of several wavelengths, which is larger than the Goos--Hänchen shift of elastically reflected beam. Unexpectedly, at selected frequencies, we found a significant increase in the value of the lateral shifts of the scattered spin-wave beams formed in the confluence process. We show that this effect is associated with the cascading nonlinear processes taking place at the edge of the film and involving the primary edge spin wave. Our results make an important contribution to the understanding of the nonlinear nature of spin waves and provide a way to exploit it in signal processing with magnons. |
| 314. | C. Jasiukiewicz, A. Sinner, I. Weymann, T. Domański, L. Chotorlishvili Phys. Rev. B, 111 , pp. 075415, 2025. @article{Jasiukiewicz2025, title = {Entanglement between quantum dots transmitted via a Majorana wire: Insights from the fermionic negativity, concurrence, and quantum mutual information}, author = {C. Jasiukiewicz and A. Sinner and I. Weymann and T. Domański and L. Chotorlishvili }, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.111.075415}, doi = {10.1103/PhysRevB.111.075415}, year = {2025}, date = {2025-02-12}, journal = {Phys. Rev. B}, volume = {111}, pages = {075415}, abstract = {We study quantum entanglement in a system comprising two quantum dots interconnected through the short topological superconducting nanowire, which hosts overlapping boundary Majorana modes. Inspecting the fermionic negativity, we analyze the variation of entanglement against the position of the energy levels of quantum dots and their hybridization with the topological superconducting nanowire. In the absence of electron correlations, the optimal entanglement occurs when the energy levels coincide with the zero-energy Majorana modes, whereas upon increasing the hybridizations, the entanglement is gradually suppressed. Such monotonous behavior is no longer valid when the quantum dot levels are detuned from the zero-energy. Under these circumstances, the quantum dots become maximally entangled for a certain optimal hybridization. Moreover, we study the thermal concurrence to explore the entanglement properties at finite temperatures. We also compute the quantum mutual information and propose recipes for robust finite-temperature entanglement transmission via Majorana modes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We study quantum entanglement in a system comprising two quantum dots interconnected through the short topological superconducting nanowire, which hosts overlapping boundary Majorana modes. Inspecting the fermionic negativity, we analyze the variation of entanglement against the position of the energy levels of quantum dots and their hybridization with the topological superconducting nanowire. In the absence of electron correlations, the optimal entanglement occurs when the energy levels coincide with the zero-energy Majorana modes, whereas upon increasing the hybridizations, the entanglement is gradually suppressed. Such monotonous behavior is no longer valid when the quantum dot levels are detuned from the zero-energy. Under these circumstances, the quantum dots become maximally entangled for a certain optimal hybridization. Moreover, we study the thermal concurrence to explore the entanglement properties at finite temperatures. We also compute the quantum mutual information and propose recipes for robust finite-temperature entanglement transmission via Majorana modes. |
| 313. | Sylwia Kudła, Vitalii K. Dugaev, Józef Barnaś, Anna Dyrdał Longitudinal magnetoresistance in graphene with random Rashba spin-orbit interaction Phys. Rev. B, 111 , pp. 075413, 2025. @article{Kudla2025, title = {Longitudinal magnetoresistance in graphene with random Rashba spin-orbit interaction}, author = {Sylwia Kudła and Vitalii K. Dugaev and Józef Barnaś and Anna Dyrdał}, url = {https://link.aps.org/doi/10.1103/PhysRevB.111.075413}, doi = {10.1103/PhysRevB.111.075413}, year = {2025}, date = {2025-02-11}, journal = {Phys. Rev. B}, volume = {111}, pages = {075413}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 312. | Piotr Trocha Scientific Reports, 15 (4904), 2025. @article{Trocha2025, title = {Spin-dependent thermoelectric properties of a hybrid ferromagnetic metal/quantum dot/topological insulator junction}, author = {Piotr Trocha}, url = {https://www.nature.com/articles/s41598-025-87931-7}, doi = {10.1038/s41598-025-87931-7}, year = {2025}, date = {2025-02-10}, journal = {Scientific Reports}, volume = {15}, number = {4904}, abstract = {The thermoelectric properties of hybrid system based on a single-level quantum dot coupled to a ferromagnetic metallic lead and attached to the surface states of a three-dimensional topological insulator are theoretically investigated. On the surface of a three-dimensional topological insulator, massless helical Dirac fermions emerge. We calculate the thermoelectric coefficients, including electrical conductance, Seebeck coefficient (thermopower), heat conductance, and the figure of merit, using the nonequilibrium Green’s function technique. The results are analyzed in terms of the emergence of new effects. The calculations are performed within the Hubbard I approximation concerning the dot’s Coulomb interactions. Additionally, the spin-dependent coupling of the quantum dot to the ferromagnetic lead lifts the spin degeneracy of the dot’s level, which influences the transport properties of the system. We incorporate this effect perturbatively to obtain the spin-dependent renormalization of the dot’s level. We also consider the case of finite spin accumulation in the ferromagnetic electrode, which leads to spin thermoelectric effects.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The thermoelectric properties of hybrid system based on a single-level quantum dot coupled to a ferromagnetic metallic lead and attached to the surface states of a three-dimensional topological insulator are theoretically investigated. On the surface of a three-dimensional topological insulator, massless helical Dirac fermions emerge. We calculate the thermoelectric coefficients, including electrical conductance, Seebeck coefficient (thermopower), heat conductance, and the figure of merit, using the nonequilibrium Green’s function technique. The results are analyzed in terms of the emergence of new effects. The calculations are performed within the Hubbard I approximation concerning the dot’s Coulomb interactions. Additionally, the spin-dependent coupling of the quantum dot to the ferromagnetic lead lifts the spin degeneracy of the dot’s level, which influences the transport properties of the system. We incorporate this effect perturbatively to obtain the spin-dependent renormalization of the dot’s level. We also consider the case of finite spin accumulation in the ferromagnetic electrode, which leads to spin thermoelectric effects. |
| 311. | Emil Siuda, Piotr Trocha Thermal Gradient Powering Spin Current in Quantum Dot-Magnetic Insulators Hybrid Journal of Superconductivity and Novel Magnetism, 38 (81), 2025. @article{Siuda2025, title = {Thermal Gradient Powering Spin Current in Quantum Dot-Magnetic Insulators Hybrid}, author = {Emil Siuda and Piotr Trocha }, url = {https://link.springer.com/article/10.1007/s10948-025-06921-y}, doi = {10.1007/s10948-025-06921-y}, year = {2025}, date = {2025-02-07}, journal = {Journal of Superconductivity and Novel Magnetism}, volume = {38}, number = {81}, abstract = {The growing energy consumption of the computational sector worldwide necessitates the search for sustainable methods of powering and performing calculations. The fast-emerging field of spin caloritronics offers a promising solution by combining the advantages of performing computations on spins instead of charges and driving these computations through temperature differences rather than voltage. Among the various approaches, spin waves and their quanta of excitations, known as magnons, are considered promising carriers of spin-encoded information. In this article, we examine the magnon current generated in a system composed of a magnetic insulator/quantum dot/magnetic insulator, driven by a small temperature difference applied between the two insulators. By expanding the magnon current in terms of the applied temperature bias, we analyze the contributions of successive terms up to the third order of the temperature difference. Each term exhibits a similar structure, consisting of a driving-like and a damping-like component. The driving-like term is dependent on the coupling strength between the quantum dot and the electrodes. We explicitly show that the second-order term of the magnon current vanishes when the couplings of the quantum dot to the magnetic insulators are equal. Overall, the first two terms are sufficient to capture the behavior of the magnon current across the full range of temperature differences. For extreme values of the temperature gradient, the approximate results align with the exact ones only when there is significant asymmetry in the coupling strengths. Finally, we demonstrate that the system can function as a spin diode, capable of rectifying the magnon current when the temperature bias is reversed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The growing energy consumption of the computational sector worldwide necessitates the search for sustainable methods of powering and performing calculations. The fast-emerging field of spin caloritronics offers a promising solution by combining the advantages of performing computations on spins instead of charges and driving these computations through temperature differences rather than voltage. Among the various approaches, spin waves and their quanta of excitations, known as magnons, are considered promising carriers of spin-encoded information. In this article, we examine the magnon current generated in a system composed of a magnetic insulator/quantum dot/magnetic insulator, driven by a small temperature difference applied between the two insulators. By expanding the magnon current in terms of the applied temperature bias, we analyze the contributions of successive terms up to the third order of the temperature difference. Each term exhibits a similar structure, consisting of a driving-like and a damping-like component. The driving-like term is dependent on the coupling strength between the quantum dot and the electrodes. We explicitly show that the second-order term of the magnon current vanishes when the couplings of the quantum dot to the magnetic insulators are equal. Overall, the first two terms are sufficient to capture the behavior of the magnon current across the full range of temperature differences. For extreme values of the temperature gradient, the approximate results align with the exact ones only when there is significant asymmetry in the coupling strengths. Finally, we demonstrate that the system can function as a spin diode, capable of rectifying the magnon current when the temperature bias is reversed. |
| 310. | Jhen-Dong Lin, Po-Chen Kuo, Neill Lambert, Adam Miranowicz, Franco Nori, Yueh-Nan Chen Non-Markovian quantum exceptional points Nature Communications, 16 (1), pp. 1289, 2025, ISSN: 2041-1723. @article{Lin2025, title = {Non-Markovian quantum exceptional points}, author = {Jhen-Dong Lin and Po-Chen Kuo and Neill Lambert and Adam Miranowicz and Franco Nori and Yueh-Nan Chen}, url = {https://doi.org/10.1038/s41467-025-56242-w}, doi = {10.1038/s41467-025-56242-w}, issn = {2041-1723}, year = {2025}, date = {2025-02-03}, journal = {Nature Communications}, volume = {16}, number = {1}, pages = {1289}, abstract = {Exceptional points (EPs) are singularities in the spectra of non-Hermitian operators where eigenvalues and eigenvectors coalesce. Open quantum systems have recently been explored as EP testbeds due to their non-Hermitian nature. However, most studies focus on the Markovian limit, leaving a gap in understanding EPs in the non-Markovian regime. This work addresses this gap by proposing a general framework based on two numerically exact descriptions of non-Markovian dynamics: the pseudomode equation of motion (PMEOM) and the hierarchical equations of motion (HEOM). The PMEOM is particularly useful due to its Lindblad-type structure, aligning with previous studies in the Markovian regime while offering deeper insights into EP identification. This framework incorporates non-Markovian effects through auxiliary degrees of freedom, enabling the discovery of additional or higher-order EPs that are inaccessible in the Markovian regime. We demonstrate the utility of this approach using the spin-boson model and linear bosonic systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Exceptional points (EPs) are singularities in the spectra of non-Hermitian operators where eigenvalues and eigenvectors coalesce. Open quantum systems have recently been explored as EP testbeds due to their non-Hermitian nature. However, most studies focus on the Markovian limit, leaving a gap in understanding EPs in the non-Markovian regime. This work addresses this gap by proposing a general framework based on two numerically exact descriptions of non-Markovian dynamics: the pseudomode equation of motion (PMEOM) and the hierarchical equations of motion (HEOM). The PMEOM is particularly useful due to its Lindblad-type structure, aligning with previous studies in the Markovian regime while offering deeper insights into EP identification. This framework incorporates non-Markovian effects through auxiliary degrees of freedom, enabling the discovery of additional or higher-order EPs that are inaccessible in the Markovian regime. We demonstrate the utility of this approach using the spin-boson model and linear bosonic systems. |
| 309. | Gianluca Gubbiotti, Anjan Barman, Sam Ladak, Cristina Bran, Dirk Grundler, Michael Huth, Harald Plank, Georg Schmidt, Sebastiaan van Dijken, Robert Streubel, Oleksandr Dobrovoloskiy, Valerio Scagnoli, Laura Heyderman, Claire Donnelly, Olav Hellwig, Lorenzo Fallarino, Benjamin M Jungfleisch, Alan Farhan, Nicolò Maccaferri, Paolo Vavassori, Peter Fischer, Riccardo Tomasello, Giovanni Finocchio, Rodolphe Clérac, Roberta Sessoli, Denys Makarov, Denis D Sheka, Maciej Krawczyk, Rodolfo Gallardo, Pedro Landeros, Massimiliano d’Aquino, Riccardo Hertel, Philipp Pirro, Florin Ciubotaru, Markus Becherer, Jack Gartside, Teruo Ono, Paolo Bortolotti, Amalio Fernández-Pacheco 2025 roadmap on 3D nanomagnetism Journal of Physics: Condensed Matter, 37 (14), pp. 143502, 2025. @article{Gubbiotti_2025, title = {2025 roadmap on 3D nanomagnetism}, author = {Gianluca Gubbiotti and Anjan Barman and Sam Ladak and Cristina Bran and Dirk Grundler and Michael Huth and Harald Plank and Georg Schmidt and Sebastiaan van Dijken and Robert Streubel and Oleksandr Dobrovoloskiy and Valerio Scagnoli and Laura Heyderman and Claire Donnelly and Olav Hellwig and Lorenzo Fallarino and Benjamin M Jungfleisch and Alan Farhan and Nicolò Maccaferri and Paolo Vavassori and Peter Fischer and Riccardo Tomasello and Giovanni Finocchio and Rodolphe Clérac and Roberta Sessoli and Denys Makarov and Denis D Sheka and Maciej Krawczyk and Rodolfo Gallardo and Pedro Landeros and Massimiliano d’Aquino and Riccardo Hertel and Philipp Pirro and Florin Ciubotaru and Markus Becherer and Jack Gartside and Teruo Ono and Paolo Bortolotti and Amalio Fernández-Pacheco}, url = {https://dx.doi.org/10.1088/1361-648X/ad9655}, doi = {10.1088/1361-648X/ad9655}, year = {2025}, date = {2025-02-01}, journal = {Journal of Physics: Condensed Matter}, volume = {37}, number = {14}, pages = {143502}, publisher = {IOP Publishing}, abstract = {The transition from planar to three-dimensional (3D) magnetic nanostructures represents a significant advancement in both fundamental research and practical applications, offering vast potential for next-generation technologies like ultrahigh-density storage, memory, logic, and neuromorphic computing. Despite being a relatively new field, the emergence of 3D nanomagnetism presents numerous opportunities for innovation, prompting the creation of a comprehensive roadmap by leading international researchers. This roadmap aims to facilitate collaboration and interdisciplinary dialogue to address challenges in materials science, physics, engineering, and computing. The roadmap comprises eighteen sections, roughly divided into three blocks. The first block explores the fundamentals of 3D nanomagnetism, focusing on recent trends in fabrication techniques and imaging methods crucial for understanding complex spin textures, curved surfaces, and small-scale interactions. Techniques such as two-photon lithography and focused electron beam-induced deposition enable the creation of intricate 3D architectures, while advanced imaging methods like electron holography and synchrotron x-ray tomography provide nanoscale spatial resolution for studying magnetization dynamics in three dimensions. Various 3D magnetic systems, including coupled multilayer systems, artificial spin-ice, magneto-plasmonic systems, topological spin textures, and molecular magnets are discussed. The second block introduces analytical and numerical methods for investigating 3D nanomagnetic structures and curvilinear systems, highlighting geometrically curved architectures, interconnected nanowire systems, and other complex geometries. Finite element methods are emphasized for capturing complex geometries, along with direct frequency domain solutions for addressing magnonic problems. The final block focuses on 3D magnonic crystals and networks, exploring their fundamental properties and potential applications in magnonic circuits, memory, and spintronics. Computational approaches using 3D nanomagnetic systems and complex topological textures in 3D spintronics are highlighted for their potential to enable faster and more energy-efficient computing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The transition from planar to three-dimensional (3D) magnetic nanostructures represents a significant advancement in both fundamental research and practical applications, offering vast potential for next-generation technologies like ultrahigh-density storage, memory, logic, and neuromorphic computing. Despite being a relatively new field, the emergence of 3D nanomagnetism presents numerous opportunities for innovation, prompting the creation of a comprehensive roadmap by leading international researchers. This roadmap aims to facilitate collaboration and interdisciplinary dialogue to address challenges in materials science, physics, engineering, and computing. The roadmap comprises eighteen sections, roughly divided into three blocks. The first block explores the fundamentals of 3D nanomagnetism, focusing on recent trends in fabrication techniques and imaging methods crucial for understanding complex spin textures, curved surfaces, and small-scale interactions. Techniques such as two-photon lithography and focused electron beam-induced deposition enable the creation of intricate 3D architectures, while advanced imaging methods like electron holography and synchrotron x-ray tomography provide nanoscale spatial resolution for studying magnetization dynamics in three dimensions. Various 3D magnetic systems, including coupled multilayer systems, artificial spin-ice, magneto-plasmonic systems, topological spin textures, and molecular magnets are discussed. The second block introduces analytical and numerical methods for investigating 3D nanomagnetic structures and curvilinear systems, highlighting geometrically curved architectures, interconnected nanowire systems, and other complex geometries. Finite element methods are emphasized for capturing complex geometries, along with direct frequency domain solutions for addressing magnonic problems. The final block focuses on 3D magnonic crystals and networks, exploring their fundamental properties and potential applications in magnonic circuits, memory, and spintronics. Computational approaches using 3D nanomagnetic systems and complex topological textures in 3D spintronics are highlighted for their potential to enable faster and more energy-efficient computing. |
| 308. | Anand Manaparambil, Andreas Weichselbaum, Jan von Delft, Ireneusz Weymann Nonequilibrium steady-state thermoelectrics of Kondo-correlated quantum dots Phys. Rev. B, 111 , pp. 035445, 2025. @article{Manaparambil2025, title = {Nonequilibrium steady-state thermoelectrics of Kondo-correlated quantum dots}, author = {Anand Manaparambil and Andreas Weichselbaum and Jan von Delft and Ireneusz Weymann}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.111.035445}, doi = {10.1103/PhysRevB.111.035445}, year = {2025}, date = {2025-01-27}, journal = {Phys. Rev. B}, volume = {111}, pages = {035445}, abstract = {The transport across a Kondo-correlated quantum dot coupled to two leads with independent temperatures and chemical potentials is studied using a controlled nonperturbative, and in this sense numerically exact, treatment based on a hybrid numerical renormalization group combined with time-dependent density matrix renormalization group (NRG-tDMRG). In the Kondo regime, for sufficiently large fixed voltage bias 𝑉≳𝑇𝐾, with 𝑇𝐾 the Kondo temperature, we find a peak in the conductance vs the temperature gradient Δ𝑇=𝑇𝑅−𝑇𝐿 across left and right lead. Focusing then on zero voltage bias but finite Δ𝑇 far beyond linear response, we reveal the dependence of the characteristic zero-bias conductance on the individual lead temperatures. We find that the finite-Δ𝑇 data behaves quantitatively similar to linear response with an effective equilibrium temperature derived from the different lead temperatures. The regime of sign changes in the Seebeck coefficient, signaling the presence of Kondo correlations, and its dependence on the individual lead temperatures provide a complete picture of the Kondo regime in the presence of finite-temperature gradients. The results from the zero-bias conductance and Seebeck coefficient studies unveil an approximate “Kondo circle” in the 𝑇𝐿/𝑇𝑅 plane as the regime within which the Kondo correlations dominate. We also study the heat current and the corresponding heat conductance vs finite Δ𝑇. We provide a polynomial fit for our numerical results for the thermocurrent as a function of the individual lead temperatures, which may be used to fit experimental data in the Kondo regime.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The transport across a Kondo-correlated quantum dot coupled to two leads with independent temperatures and chemical potentials is studied using a controlled nonperturbative, and in this sense numerically exact, treatment based on a hybrid numerical renormalization group combined with time-dependent density matrix renormalization group (NRG-tDMRG). In the Kondo regime, for sufficiently large fixed voltage bias 𝑉≳𝑇𝐾, with 𝑇𝐾 the Kondo temperature, we find a peak in the conductance vs the temperature gradient Δ𝑇=𝑇𝑅−𝑇𝐿 across left and right lead. Focusing then on zero voltage bias but finite Δ𝑇 far beyond linear response, we reveal the dependence of the characteristic zero-bias conductance on the individual lead temperatures. We find that the finite-Δ𝑇 data behaves quantitatively similar to linear response with an effective equilibrium temperature derived from the different lead temperatures. The regime of sign changes in the Seebeck coefficient, signaling the presence of Kondo correlations, and its dependence on the individual lead temperatures provide a complete picture of the Kondo regime in the presence of finite-temperature gradients. The results from the zero-bias conductance and Seebeck coefficient studies unveil an approximate “Kondo circle” in the 𝑇𝐿/𝑇𝑅 plane as the regime within which the Kondo correlations dominate. We also study the heat current and the corresponding heat conductance vs finite Δ𝑇. We provide a polynomial fit for our numerical results for the thermocurrent as a function of the individual lead temperatures, which may be used to fit experimental data in the Kondo regime. |
| 307. | Piotr Trocha, Thibaut Jonckheere, Jérôme Rech, Thierry Martin Thermoelectric properties of a quantum dot attached to normal metal and topological superconductor Scientific Reports, 15 (3068), 2025. @article{Trocha2025b, title = {Thermoelectric properties of a quantum dot attached to normal metal and topological superconductor}, author = {Piotr Trocha and Thibaut Jonckheere and Jérôme Rech and Thierry Martin}, url = {https://www.nature.com/articles/s41598-024-84770-w}, doi = {10.1038/s41598-024-84770-w}, year = {2025}, date = {2025-01-24}, journal = {Scientific Reports}, volume = {15}, number = {3068}, abstract = {The thermoelectric properties of hybrid systems based on a single-level quantum dot coupled to a normal-metal/half-metallic lead and attached to a topological superconductor wire are investigated. The topological superconductor wire is modeled by a spinless p-wave superconductor which hosts both a Majorana bound state at its extremity and above gap quasiparticle excitations. The main interest of our investigation is to study the interplay of sub-gap and single-particle tunneling processes and their contributions to the thermoelectric response of the considered system. The above gap tunneling driven by a temperature gradient is responsible for relatively large thermopower, whereas sub-gap processes only indirectly influence the thermoelectric response. The thermoelectric coefficients, including electric conductance, Seebeck coefficient (thermopower), heat conductance, and figure of merit, are calculated by means of the non-equilibrium Green’s function technique and the temperature dependence of the superconducting gap is considered within the BCS theory. We also consider the system out of equilibrium working as a heat engine. The output power and the corresponding efficiency are presented. Interestingly, under certain conditions, it is possible to extract more power in the superconducting phase than in the normal phase, with comparable efficiency.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The thermoelectric properties of hybrid systems based on a single-level quantum dot coupled to a normal-metal/half-metallic lead and attached to a topological superconductor wire are investigated. The topological superconductor wire is modeled by a spinless p-wave superconductor which hosts both a Majorana bound state at its extremity and above gap quasiparticle excitations. The main interest of our investigation is to study the interplay of sub-gap and single-particle tunneling processes and their contributions to the thermoelectric response of the considered system. The above gap tunneling driven by a temperature gradient is responsible for relatively large thermopower, whereas sub-gap processes only indirectly influence the thermoelectric response. The thermoelectric coefficients, including electric conductance, Seebeck coefficient (thermopower), heat conductance, and figure of merit, are calculated by means of the non-equilibrium Green’s function technique and the temperature dependence of the superconducting gap is considered within the BCS theory. We also consider the system out of equilibrium working as a heat engine. The output power and the corresponding efficiency are presented. Interestingly, under certain conditions, it is possible to extract more power in the superconducting phase than in the normal phase, with comparable efficiency. |
| 306. | Mateusz Gołębiewski, Krzysztof Szulc, Maciej Krawczyk Magnetic field controlled surface localization of ferromagnetic resonance modes in 3D nanostructures Acta Materialia, 283 , pp. 120499, 2025, ISSN: 1359-6454. @article{GOLEBIEWSKI2025120499, title = {Magnetic field controlled surface localization of ferromagnetic resonance modes in 3D nanostructures}, author = {Mateusz Gołębiewski and Krzysztof Szulc and Maciej Krawczyk}, url = {https://www.sciencedirect.com/science/article/pii/S1359645424008486}, doi = {https://doi.org/10.1016/j.actamat.2024.120499}, issn = {1359-6454}, year = {2025}, date = {2025-01-15}, journal = {Acta Materialia}, volume = {283}, pages = {120499}, abstract = {By extending the current understanding and use of magnonics beyond conventional planar systems, we demonstrate the surface localization of ferromagnetic resonance (FMR) modes through the design of complex three-dimensional nanostructures. Using micromagnetic simulations, we systematically investigate woodpile-like scaffolds and gyroids — periodic chiral entities characterized by their triple junctions. The study highlights the critical role of demagnetizing fields and exchange energy in determining the FMR responses of 3D nanosystems, especially the strongly asymmetric distribution of the spin-wave mode over the system’s height. Importantly, the top–bottom dynamic switching of the surface mode localization across the structures in response to changes in magnetic field orientation provides a new method for controlling magnetization dynamics. The results demonstrate the critical role of the geometric features in dictating the dynamic magnetic behavior of three-dimensional nanostructures, paving the way for both experimental exploration and practical advances in 3D magnonics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } By extending the current understanding and use of magnonics beyond conventional planar systems, we demonstrate the surface localization of ferromagnetic resonance (FMR) modes through the design of complex three-dimensional nanostructures. Using micromagnetic simulations, we systematically investigate woodpile-like scaffolds and gyroids — periodic chiral entities characterized by their triple junctions. The study highlights the critical role of demagnetizing fields and exchange energy in determining the FMR responses of 3D nanosystems, especially the strongly asymmetric distribution of the spin-wave mode over the system’s height. Importantly, the top–bottom dynamic switching of the surface mode localization across the structures in response to changes in magnetic field orientation provides a new method for controlling magnetization dynamics. The results demonstrate the critical role of the geometric features in dictating the dynamic magnetic behavior of three-dimensional nanostructures, paving the way for both experimental exploration and practical advances in 3D magnonics. |
| 305. | Jacek Baranowski, Bogusław Mróz, Sławomir Mielcarek, I Iatsunskyi, Aleksandra Trzaskowska Scientific Reports, 15 (1), pp. 1358, 2025, ISSN: 2045-2322. @article{Baranowski2025, title = {High resolution Brillouin spectroscopy of the surface acoustic waves in Sb2Te3 van der Waals single crystals}, author = {Jacek Baranowski and Bogusław Mróz and Sławomir Mielcarek and I Iatsunskyi and Aleksandra Trzaskowska}, url = {https://doi.org/10.1038/s41598-025-85742-4}, doi = {10.1038/s41598-025-85742-4}, issn = {2045-2322}, year = {2025}, date = {2025-01-08}, journal = {Scientific Reports}, volume = {15}, number = {1}, pages = {1358}, abstract = {High-resolution Brillouin spectroscopy was employed to investigate the anisotropy in surface wave velocities within a bulk single crystal of Sb2Te3, a well-known layered van der Waals material. By leveraging the bulk elastic constants derived from various simulation methods, we were able to theoretically calculate the distribution of surface acoustic phonon velocities on the cleavage plane of the material. Upon analyzing multiple simulation results, it became evident that the most significant discrepancies arose in the calculations of the elastic constant c33, with values ranging from 48 to 98 GPa. Consequently, a direct measurement of the c33 elastic constant for Sb2Te3 was attempted. Through our ellipsometry results, we determined both the real and imaginary components of the refractive index, leading to an experimental determination of the c33 elastic constant, which was found to be 47.9 GPa. Additionally the results of the conducted studies enabled the analytical determination of all components of the elastic property tensor of the investigated material.}, keywords = {}, pubstate = {published}, tppubtype = {article} } High-resolution Brillouin spectroscopy was employed to investigate the anisotropy in surface wave velocities within a bulk single crystal of Sb2Te3, a well-known layered van der Waals material. By leveraging the bulk elastic constants derived from various simulation methods, we were able to theoretically calculate the distribution of surface acoustic phonon velocities on the cleavage plane of the material. Upon analyzing multiple simulation results, it became evident that the most significant discrepancies arose in the calculations of the elastic constant c33, with values ranging from 48 to 98 GPa. Consequently, a direct measurement of the c33 elastic constant for Sb2Te3 was attempted. Through our ellipsometry results, we determined both the real and imaginary components of the refractive index, leading to an experimental determination of the c33 elastic constant, which was found to be 47.9 GPa. Additionally the results of the conducted studies enabled the analytical determination of all components of the elastic property tensor of the investigated material. |
| 304. | Chun-Wang Wu, Man-Chao Zhang, Yan-Li Zhou, Ting Chen, Ran Huang, Yi Xie, Wen-bo Su, Bao-Quan Ou, Wei Wu, Adam Miranowicz, Franco Nori, Jie Zhang, Hui Jing, Ping-Xing Chen Observation of quantum temporal correlations well beyond Lüders bound Phys. Rev. Res., 7 , pp. 013058, 2025. @article{Wu2025, title = {Observation of quantum temporal correlations well beyond Lüders bound}, author = {Chun-Wang Wu and Man-Chao Zhang and Yan-Li Zhou and Ting Chen and Ran Huang and Yi Xie and Wen-bo Su and Bao-Quan Ou and Wei Wu and Adam Miranowicz and Franco Nori and Jie Zhang and Hui Jing and Ping-Xing Chen}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.7.013058}, doi = {10.1103/PhysRevResearch.7.013058}, year = {2025}, date = {2025-01-01}, journal = {Phys. Rev. Res.}, volume = {7}, pages = {013058}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 303. | Dariia Popadiuk, Andriy Vovk, Sergey A Bunyaev, Gleb N Kakazei, João P Araújo, Pavel Strichovanec, Pedro A Algarabel, Vladimir Golub, Anatolii F Kravets, Vladislav Korenivski, Aleksandra Trzaskowska Journal of Applied Physics, 137 (12), pp. 123902, 2025, ISSN: 0021-8979. @article{10.1063/5.0255241, title = {Spin waves in Co2FeGe films}, author = {Dariia Popadiuk and Andriy Vovk and Sergey A Bunyaev and Gleb N Kakazei and João P Araújo and Pavel Strichovanec and Pedro A Algarabel and Vladimir Golub and Anatolii F Kravets and Vladislav Korenivski and Aleksandra Trzaskowska}, url = {https://doi.org/10.1063/5.0255241}, doi = {10.1063/5.0255241}, issn = {0021-8979}, year = {2025}, date = {2025-01-01}, journal = {Journal of Applied Physics}, volume = {137}, number = {12}, pages = {123902}, abstract = {The dynamic magnetic properties of full Heusler alloy thin films of Co 2FeGe, grown on MgO (001) substrates under different thermal conditions, were investigated. Brillouin light scattering and ferromagnetic resonance measurements revealed that depositing at room temperature followed by annealing at 300 °C for 1 h produces the best results for maximizing magnetization, exchange stiffness, and minimizing spin-dynamic dissipation in the films, which are desirable characteristics for high-speed spintronic devices. Additionally, strong hybridization of spin waves in the Damon–Eshbach geometry was observed, which is attractive for applications in magnonic signal processing circuits.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The dynamic magnetic properties of full Heusler alloy thin films of Co 2FeGe, grown on MgO (001) substrates under different thermal conditions, were investigated. Brillouin light scattering and ferromagnetic resonance measurements revealed that depositing at room temperature followed by annealing at 300 °C for 1 h produces the best results for maximizing magnetization, exchange stiffness, and minimizing spin-dynamic dissipation in the films, which are desirable characteristics for high-speed spintronic devices. Additionally, strong hybridization of spin waves in the Damon–Eshbach geometry was observed, which is attractive for applications in magnonic signal processing circuits. |
2024 |
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| 302. | P Graczyk, Bivas Rana, Aleksandra Trzaskowska, B K Mahato, Jarosław W. Kłos, Maciej Krawczyk, A Barman Ultrasonics, 148 , pp. 107522, 2024, ISSN: 0041-624X. @article{GRACZYK2025107522, title = {Optical excitation and detection of high-frequency Sezawa modes in Si/SiO2 system decorated with Ni80Fe20 nanodot arrays}, author = {P Graczyk and Bivas Rana and Aleksandra Trzaskowska and B K Mahato and Jarosław W. Kłos and Maciej Krawczyk and A Barman}, url = {https://www.sciencedirect.com/science/article/pii/S0041624X24002853}, doi = {https://doi.org/10.1016/j.ultras.2024.107522}, issn = {0041-624X}, year = {2024}, date = {2024-12-04}, journal = {Ultrasonics}, volume = {148}, pages = {107522}, abstract = {Surface acoustic waves have emerged as one of the potential candidates for the development of next-generation wave-based information and computing technologies. For practical devices, it is essential to develop the excitation techniques for different types of surface acoustic waves, especially at higher microwave frequencies, and to tailor their frequency versus wave vector characteristics. We show that this can be done by using ultrashort laser pulses incident on the surface of a multilayer decorated with a periodic array of metallic nanodots. Specifically, we study surface acoustic waves in the dielectric substrate Si/SiO2 decorated with a square lattice of thin Ni80Fe20 (Py) dots. Using a femtosecond laser-based optical pump–probe measurement, we detect a number of high-frequency phononic modes. By performing finite element simulations, we identify them as Sezawa modes from the second and third Brillouin zone in addition to the modes confined within the Py dots. The frequency of the Sezawa modes strongly depends on the period of the Py dots and varies in the range between 5 to 15 GHz. Both types of waves cover the same frequency range for Py dots with period less than 400 nm, providing a promising system for magnetoelastic studies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Surface acoustic waves have emerged as one of the potential candidates for the development of next-generation wave-based information and computing technologies. For practical devices, it is essential to develop the excitation techniques for different types of surface acoustic waves, especially at higher microwave frequencies, and to tailor their frequency versus wave vector characteristics. We show that this can be done by using ultrashort laser pulses incident on the surface of a multilayer decorated with a periodic array of metallic nanodots. Specifically, we study surface acoustic waves in the dielectric substrate Si/SiO2 decorated with a square lattice of thin Ni80Fe20 (Py) dots. Using a femtosecond laser-based optical pump–probe measurement, we detect a number of high-frequency phononic modes. By performing finite element simulations, we identify them as Sezawa modes from the second and third Brillouin zone in addition to the modes confined within the Py dots. The frequency of the Sezawa modes strongly depends on the period of the Py dots and varies in the range between 5 to 15 GHz. Both types of waves cover the same frequency range for Py dots with period less than 400 nm, providing a promising system for magnetoelastic studies. |
| 301. | Anna Krzyżewska, Anna Dyrdał physica status solidi (RRL) – Rapid Research Letters, 18 (12), pp. 2400123, 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 = {2024-12-03}, journal = {physica status solidi (RRL) – Rapid Research Letters}, volume = {18}, number = {12}, pages = {2400123}, 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. |
| 300. | Shilan Abo, Patrycja Tulewicz, Karol Bartkiewicz, Şahin K Özdemir, Adam Miranowicz Experimental Liouvillian exceptional points in a quantum system without Hamiltonian singularities New Journal of Physics, 26 (12), pp. 123032, 2024. @article{Abo_2024, title = {Experimental Liouvillian exceptional points in a quantum system without Hamiltonian singularities}, author = {Shilan Abo and Patrycja Tulewicz and Karol Bartkiewicz and Şahin K Özdemir and Adam Miranowicz}, url = {https://dx.doi.org/10.1088/1367-2630/ad98b6}, doi = {10.1088/1367-2630/ad98b6}, year = {2024}, date = {2024-12-01}, journal = {New Journal of Physics}, volume = {26}, number = {12}, pages = {123032}, publisher = {IOP Publishing}, abstract = {Hamiltonian exceptional points (HEPs) are spectral degeneracies of non-Hermitian Hamiltonians describing classical and semiclassical open systems with losses and/or gain. However, this definition overlooks the occurrence of quantum jumps in the evolution of open quantum systems. These quantum effects are properly accounted for by considering quantum Liouvillians and their exceptional points (LEPs). Specifically, an LEP corresponds to the coalescence of two or more eigenvalues and the corresponding eigenmatrices of a given Liouvillian at critical values of external parameters (Minganti et al 2019 Phys. Rev. A 100 062131). Here, we explicitly describe how standard quantum process tomography, which reveals the dynamics of a quantum system, can be readily applied to detect and characterize quantum LEPs of quantum non-Hermitian systems. We conducted experiments on an IBM quantum processor to implement a prototype model with one-, two-, and three qubits simulating the decay of a single qubit through competing channels, resulting in LEPs but not HEPs. Subsequently, we performed tomographic reconstruction of the corresponding experimental Liouvillian and its LEPs using both single- and two-qubit operations. This example underscores the efficacy of process tomography in tuning and observing LEPs even in the absence of HEPs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hamiltonian exceptional points (HEPs) are spectral degeneracies of non-Hermitian Hamiltonians describing classical and semiclassical open systems with losses and/or gain. However, this definition overlooks the occurrence of quantum jumps in the evolution of open quantum systems. These quantum effects are properly accounted for by considering quantum Liouvillians and their exceptional points (LEPs). Specifically, an LEP corresponds to the coalescence of two or more eigenvalues and the corresponding eigenmatrices of a given Liouvillian at critical values of external parameters (Minganti et al 2019 Phys. Rev. A 100 062131). Here, we explicitly describe how standard quantum process tomography, which reveals the dynamics of a quantum system, can be readily applied to detect and characterize quantum LEPs of quantum non-Hermitian systems. We conducted experiments on an IBM quantum processor to implement a prototype model with one-, two-, and three qubits simulating the decay of a single qubit through competing channels, resulting in LEPs but not HEPs. Subsequently, we performed tomographic reconstruction of the corresponding experimental Liouvillian and its LEPs using both single- and two-qubit operations. This example underscores the efficacy of process tomography in tuning and observing LEPs even in the absence of HEPs. |
| 299. | Xin Wang, Jia-Qi Li, Tao Liu, Adam Miranowicz, Franco Nori Long-range four-body interactions in structured nonlinear photonic waveguides Phys. Rev. Res., 6 , pp. 043226, 2024. @article{Wang24prr, title = {Long-range four-body interactions in structured nonlinear photonic waveguides}, author = {Xin Wang and Jia-Qi Li and Tao Liu and Adam Miranowicz and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.6.043226}, doi = {10.1103/PhysRevResearch.6.043226}, year = {2024}, date = {2024-12-01}, journal = {Phys. Rev. Res.}, volume = {6}, pages = {043226}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 298. | Wei Qin, Adam Miranowicz, Franco Nori Exponentially Improved Dispersive Qubit Readout with Squeezed Light Phys. Rev. Lett., 133 , pp. 233605, 2024. @article{Wei2024prr, title = {Exponentially Improved Dispersive Qubit Readout with Squeezed Light}, author = {Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.133.233605}, doi = {10.1103/PhysRevLett.133.233605}, year = {2024}, date = {2024-12-01}, journal = {Phys. Rev. Lett.}, volume = {133}, pages = {233605}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 297. | Ryszard Gieniusz, Paweł Gruszecki, Jan Kisielewski, Anuj Kumar Dhiman, Michal Matczak, Zbigniew Kurant, Iosif Sveklo, Urszula Guzowska, Maria Tekielak, Maciej Krawczyk, Feliks Stobiecki, Andrzej Maziewski Spin wave frequency hysteresis in Ir/Co/Pt multilayers with Dzyaloshinskii-Moriya interaction Phys. Rev. B, 110 , pp. 184410, 2024. @article{PhysRevB.110.184410, title = {Spin wave frequency hysteresis in Ir/Co/Pt multilayers with Dzyaloshinskii-Moriya interaction}, author = {Ryszard Gieniusz and Paweł Gruszecki and Jan Kisielewski and Anuj Kumar Dhiman and Michal Matczak and Zbigniew Kurant and Iosif Sveklo and Urszula Guzowska and Maria Tekielak and Maciej Krawczyk and Feliks Stobiecki and Andrzej Maziewski}, url = {https://link.aps.org/doi/10.1103/PhysRevB.110.184410}, doi = {10.1103/PhysRevB.110.184410}, year = {2024}, date = {2024-11-14}, journal = {Phys. Rev. B}, volume = {110}, pages = {184410}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 296. | Bivas Rana, YoshiChika Otani Development of Magnonics with Voltage-Controlled Magnetic Anisotropy Bandyopadhyay, Supriyo, Barman, Anjan (Ed.): Nanomagnets as Dynamical Systems: Physics and Applications, pp. 71–96, Springer Nature Switzerland, Cham, 2024, ISBN: 978-3-031-73191-4. @inbook{Rana2024, title = {Development of Magnonics with Voltage-Controlled Magnetic Anisotropy}, author = {Bivas Rana and YoshiChika Otani}, editor = {Supriyo Bandyopadhyay and Anjan Barman}, url = {https://doi.org/10.1007/978-3-031-73191-4_3}, doi = {10.1007/978-3-031-73191-4_3}, isbn = {978-3-031-73191-4}, year = {2024}, date = {2024-11-10}, booktitle = {Nanomagnets as Dynamical Systems: Physics and Applications}, pages = {71--96}, publisher = {Springer Nature Switzerland}, address = {Cham}, abstract = {This chapter discusses the origin and essential features of interfacial magnetic anisotropies and voltage-controlled magnetic anisotropy (VCMAVoltage control of magnetic anisotropy (VCMA)) in ultrathin ferromagnetFerromagnet/oxide heterostructures. Various other electric field-induced methods for controlling magnetic properties and the advantages of VCMAVoltage control of magnetic anisotropy (VCMA) over them are thoroughly discussed. The recent progress of magnonics with VCMAVoltage control of magnetic anisotropy (VCMA) is described in detail. In particular, we discuss the linear and parametric excitation of ferromagnetic and spin waveSpin wave (SW) resonance; the essential properties of spin wavesSpin wave (SW) guided through reconfigurable nanochannels; the manipulation of spin waveSpin wave (SW) frequency, phase, wavevector, magnonic band structures, and damping parameters in detail. A brief discussion follows on the excitation and manipulation of spin wavesSpin wave (SW) by various other direct and indirect electric field-induced methods. The chapter concludes by briefly describing some open challenges in this field.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } This chapter discusses the origin and essential features of interfacial magnetic anisotropies and voltage-controlled magnetic anisotropy (VCMAVoltage control of magnetic anisotropy (VCMA)) in ultrathin ferromagnetFerromagnet/oxide heterostructures. Various other electric field-induced methods for controlling magnetic properties and the advantages of VCMAVoltage control of magnetic anisotropy (VCMA) over them are thoroughly discussed. The recent progress of magnonics with VCMAVoltage control of magnetic anisotropy (VCMA) is described in detail. In particular, we discuss the linear and parametric excitation of ferromagnetic and spin waveSpin wave (SW) resonance; the essential properties of spin wavesSpin wave (SW) guided through reconfigurable nanochannels; the manipulation of spin waveSpin wave (SW) frequency, phase, wavevector, magnonic band structures, and damping parameters in detail. A brief discussion follows on the excitation and manipulation of spin wavesSpin wave (SW) by various other direct and indirect electric field-induced methods. The chapter concludes by briefly describing some open challenges in this field. |
| 295. | Sreedevi Janardhanan, Maciej Krawczyk, Aleksandra Trzaskowska Spin-Wave Dynamics in Ultra-thin Ferromagnetic Films, Patterned, and Non-patterned Bandyopadhyay, Supriyo, Barman, Anjan (Ed.): Nanomagnets as Dynamical Systems: Physics and Applications, pp. 33–69, Springer Nature Switzerland, Cham, 2024, ISBN: 978-3-031-73191-4. @inbook{Janardhanan2024b, title = {Spin-Wave Dynamics in Ultra-thin Ferromagnetic Films, Patterned, and Non-patterned}, author = {Sreedevi Janardhanan and Maciej Krawczyk and Aleksandra Trzaskowska}, editor = {Supriyo Bandyopadhyay and Anjan Barman}, url = {https://doi.org/10.1007/978-3-031-73191-4_2}, doi = {10.1007/978-3-031-73191-4_2}, isbn = {978-3-031-73191-4}, year = {2024}, date = {2024-11-10}, booktitle = {Nanomagnets as Dynamical Systems: Physics and Applications}, pages = {33--69}, publisher = {Springer Nature Switzerland}, address = {Cham}, abstract = {Exploring spin-waveSpin wave (SW) dynamics opens new avenues for technological applications across various fields. This chapter provides a comprehensive review of spin-waveSpin wave (SW) dynamics in both patterned and non-patterned ferromagnetic thin films, and emphasizes the significance of perpendicular magnetic anisotropyPerpendicular magnetic anisotropy (PMA) in this context as well. The chapter begins with an overview of the basic concept and relevance of spin wavesSpin wave (SW), followed by a detailed discussion of Brillouin light scatteringBrillouin light scattering (BLS) methodology. We explore the unique properties of spin wavesSpin wave (SW) in patterned films, such as magnonic crystalsMagnonic crystals (MC), and a comparative study with the behaviour in continuous films has been presented in detail. The future perspective from technological point of view of spin-wave research is vast, ranging from high-frequency data transmission to quantum information processing. Here we highlighted applications encompass spin-wave logic devices, magnonic waveguide, quantum computingSpin wave computing, and the role of spin wavesSpin wave (SW) in the development of novel materials with tailored magnetic properties. Finally, this review addresses the challenges associated with achieving precise control over spin-waveSpin wave (SW) propagation, elucidating spin-waveSpin wave (SW) interactions at the nanoscale, and integrating spin-waveSpin wave (SW) technology with existing technological frameworks.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } Exploring spin-waveSpin wave (SW) dynamics opens new avenues for technological applications across various fields. This chapter provides a comprehensive review of spin-waveSpin wave (SW) dynamics in both patterned and non-patterned ferromagnetic thin films, and emphasizes the significance of perpendicular magnetic anisotropyPerpendicular magnetic anisotropy (PMA) in this context as well. The chapter begins with an overview of the basic concept and relevance of spin wavesSpin wave (SW), followed by a detailed discussion of Brillouin light scatteringBrillouin light scattering (BLS) methodology. We explore the unique properties of spin wavesSpin wave (SW) in patterned films, such as magnonic crystalsMagnonic crystals (MC), and a comparative study with the behaviour in continuous films has been presented in detail. The future perspective from technological point of view of spin-wave research is vast, ranging from high-frequency data transmission to quantum information processing. Here we highlighted applications encompass spin-wave logic devices, magnonic waveguide, quantum computingSpin wave computing, and the role of spin wavesSpin wave (SW) in the development of novel materials with tailored magnetic properties. Finally, this review addresses the challenges associated with achieving precise control over spin-waveSpin wave (SW) propagation, elucidating spin-waveSpin wave (SW) interactions at the nanoscale, and integrating spin-waveSpin wave (SW) technology with existing technological frameworks. |
| 294. | Marceli Kaczmarski, Jacek Jenczyk, Bogusław Mróz Phason and Amplitudon Modes in K3Na(SeO4)2 Crystal Symmetry, 16 (11), 2024, ISSN: 2073-8994. @article{sym16111482, title = {Phason and Amplitudon Modes in K3Na(SeO4)2 Crystal}, author = {Marceli Kaczmarski and Jacek Jenczyk and Bogusław Mróz}, url = {https://www.mdpi.com/2073-8994/16/11/1482}, doi = {10.3390/sym16111482}, issn = {2073-8994}, year = {2024}, date = {2024-11-06}, journal = {Symmetry}, volume = {16}, number = {11}, abstract = {For the first time, the Nambu–Goldstone optical mode has been observed in ferroelastic crystals. The amplitudon and phason modes were identified in the Raman spectra of the K3Na(SeO4)2 (KNSe) crystal. We discuss the occurrence of such lattice vibration with regard to the possible presence of an incommensurate (IC) phase. The potential scenario of the dynamics of the SO4 tetrahedron leading to the appearance of an IC phase, accompanied by critical temperature behavior of two external vibrations of Ag symmetry, is given together with the molecular mechanism of the phase transitions in the material studied. The effect of the spatial reorganization of the crystal lattice associated with the ferroelastic domains of the KNSe crystal of W and W′ types is also discussed. We show that the emergence of such a domain structure may also be a source of incommensurability.}, keywords = {}, pubstate = {published}, tppubtype = {article} } For the first time, the Nambu–Goldstone optical mode has been observed in ferroelastic crystals. The amplitudon and phason modes were identified in the Raman spectra of the K3Na(SeO4)2 (KNSe) crystal. We discuss the occurrence of such lattice vibration with regard to the possible presence of an incommensurate (IC) phase. The potential scenario of the dynamics of the SO4 tetrahedron leading to the appearance of an IC phase, accompanied by critical temperature behavior of two external vibrations of Ag symmetry, is given together with the molecular mechanism of the phase transitions in the material studied. The effect of the spatial reorganization of the crystal lattice associated with the ferroelastic domains of the KNSe crystal of W and W′ types is also discussed. We show that the emergence of such a domain structure may also be a source of incommensurability. |
| 293. | Anuj K Dhiman, Nikodem Leśniewski, Ryszard Gieniusz, Jan Kisielewski, Piotr Mazalski, Zbigniew Kurant, Michał Matczak, Feliks Stobiecki, Maciej Krawczyk, Artem Lynnyk, Andrzej Maziewski, Paweł Gruszecki APL Materials, 12 (11), pp. 111106, 2024, ISSN: 2166-532X. @article{10.1063/5.0227380, title = {Reconfigurable magnonic crystals: Spin wave propagation in Pt/Co multilayer in saturated and stripe domain phase}, author = {Anuj K Dhiman and Nikodem Leśniewski and Ryszard Gieniusz and Jan Kisielewski and Piotr Mazalski and Zbigniew Kurant and Michał Matczak and Feliks Stobiecki and Maciej Krawczyk and Artem Lynnyk and Andrzej Maziewski and Paweł Gruszecki}, url = {https://doi.org/10.1063/5.0227380}, doi = {10.1063/5.0227380}, issn = {2166-532X}, year = {2024}, date = {2024-11-04}, journal = {APL Materials}, volume = {12}, number = {11}, pages = {111106}, abstract = {To control the spin wave (SW) propagation, external energy sources such as magnetic fields, electric currents, or complex nanopatterning are used, which can be challenging at the deep nanoscale level. In this work, we overcome such limitations by demonstrating SW propagation in Pt/Co multilayers at a remanent state controlled by stripe domain patterns, using Brillouin light scattering and micromagnetic simulations. We show that parallel stripes with a periodicity around 100 nm exhibit reconfigurability, as the stripes can be rotated by applying the in-plane field without damaging their shape. This allows us to study SW propagation perpendicular and parallel to the stripes. We observe multimodal SW spectra—three bands in perpendicular and five in parallel geometry. Numerical results allow us to identify all observed modes and to explain the differences between two configurations by the unequal contribution of all three magnetization components in the SW dynamics. We find that the experimentally measured non-reciprocal dispersion (for the wavevector perpendicular to the stripes) is not the breaking of time-symmetry but the asymmetry in intensity of the measured signals of two different low-frequency modes, which is due to the inhomogeneous SW amplitude distribution over the multilayer thickness and the limited light penetration depth. Our results pave the way for easy reprogrammability and high energy efficiency in nanomagnonics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } To control the spin wave (SW) propagation, external energy sources such as magnetic fields, electric currents, or complex nanopatterning are used, which can be challenging at the deep nanoscale level. In this work, we overcome such limitations by demonstrating SW propagation in Pt/Co multilayers at a remanent state controlled by stripe domain patterns, using Brillouin light scattering and micromagnetic simulations. We show that parallel stripes with a periodicity around 100 nm exhibit reconfigurability, as the stripes can be rotated by applying the in-plane field without damaging their shape. This allows us to study SW propagation perpendicular and parallel to the stripes. We observe multimodal SW spectra—three bands in perpendicular and five in parallel geometry. Numerical results allow us to identify all observed modes and to explain the differences between two configurations by the unequal contribution of all three magnetization components in the SW dynamics. We find that the experimentally measured non-reciprocal dispersion (for the wavevector perpendicular to the stripes) is not the breaking of time-symmetry but the asymmetry in intensity of the measured signals of two different low-frequency modes, which is due to the inhomogeneous SW amplitude distribution over the multilayer thickness and the limited light penetration depth. Our results pave the way for easy reprogrammability and high energy efficiency in nanomagnonics. |
| 292. | Wanhua Su, Wei Qin, Adam Miranowicz, Tao Li, Franco Nori Heralded nonlocal quantum gates for distributed quantum computation in a decoherence-free subspace Phys. Rev. A, 110 , pp. 052612, 2024. @article{Su2024pra, title = {Heralded nonlocal quantum gates for distributed quantum computation in a decoherence-free subspace}, author = {Wanhua Su and Wei Qin and Adam Miranowicz and Tao Li and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevA.110.052612}, doi = {10.1103/PhysRevA.110.052612}, year = {2024}, date = {2024-11-01}, journal = {Phys. Rev. A}, volume = {110}, pages = {052612}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 291. | Stefan Stagraczyński, Pavel Baláž, Mirali Jafari, Józef Barnaś, Anna Dyrdał Scientific Reports, 14 , pp. 25552, 2024. @article{Stagraczynski2024, title = {Magnetic ordering and dynamics in monolayers and bilayers of chromium trihalides: atomistic simulations approach}, author = {Stefan Stagraczyński and Pavel Baláž and Mirali Jafari and Józef Barnaś and Anna Dyrdał}, url = {https://doi.org/10.1038/s41598-024-75501-2}, doi = {10.1038/s41598-024-75501-2}, year = {2024}, date = {2024-10-26}, journal = {Scientific Reports}, volume = {14}, pages = {25552}, abstract = {We analyze magnetic properties of monolayers and bilayers of chromium iodide, CrI3, in two different stacking configurations: AA and rhombohedral ones. Our main focus is on the corresponding Curie temperatures, hysteresis curves, equilibrium spin structures, and spin wave excitations. To obtain all these magnetic characteristic, we employ the atomistic spin dynamics and Monte Carlo simulation techniques. The model Hamiltonian includes isotropic exchange coupling, magnetic anisotropy, and Dzyaloshinskii-Moriya interaction. As the latter interaction is relatively weak in pristine CrI3, we consider a more general case, when the Dzyaloshinskii-Moriya interaction is enhanced externally (e.g. due to gate voltage, mechanical strain, or proximity effects). An important issue of the analysis is the correlation between hysteresis curves and spin configurations in the system, as well as formation of the skyrmion textures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We analyze magnetic properties of monolayers and bilayers of chromium iodide, CrI3, in two different stacking configurations: AA and rhombohedral ones. Our main focus is on the corresponding Curie temperatures, hysteresis curves, equilibrium spin structures, and spin wave excitations. To obtain all these magnetic characteristic, we employ the atomistic spin dynamics and Monte Carlo simulation techniques. The model Hamiltonian includes isotropic exchange coupling, magnetic anisotropy, and Dzyaloshinskii-Moriya interaction. As the latter interaction is relatively weak in pristine CrI3, we consider a more general case, when the Dzyaloshinskii-Moriya interaction is enhanced externally (e.g. due to gate voltage, mechanical strain, or proximity effects). An important issue of the analysis is the correlation between hysteresis curves and spin configurations in the system, as well as formation of the skyrmion textures. |
| 290. | Yulia Kharlan, Krzysztof Szulc, Jarosław W Kłos, Grzegorz Centała Tunable magnonic crystal in a hybrid superconductor-ferrimagnet nanostructure Scientific Reports, 14 (1), pp. 25594, 2024, ISSN: 2045-2322. @article{Kharlan2024, title = {Tunable magnonic crystal in a hybrid superconductor-ferrimagnet nanostructure}, author = {Yulia Kharlan and Krzysztof Szulc and Jarosław W Kłos and Grzegorz Centała}, url = {https://doi.org/10.1038/s41598-024-75492-0}, doi = {10.1038/s41598-024-75492-0}, issn = {2045-2322}, year = {2024}, date = {2024-10-26}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {25594}, abstract = {One of the most intriguing properties of magnonic systems is their reconfigurability, where an external magnetic field alters the static magnetic configuration to influence magnetization dynamics. In this paper, we present an alternative approach to tunable magnonic systems. We studied theoretically and numerically a magnonic crystal induced within a uniform magnetic layer by a periodic magnetic field pattern created by the sequence of superconducting strips. We showed that the spin-wave spectrum can be tuned by the inhomogeneous stray field of the superconductor in response to a small uniform external magnetic field. Additionally, we demonstrated that modifying the width of superconducting strips and separation between them leads to the changes in the internal field which are unprecedented in conventional magnonic structures. The paper presents the results of semi-analytical calculations for realistic structures, which are verified by finite-element method computations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } One of the most intriguing properties of magnonic systems is their reconfigurability, where an external magnetic field alters the static magnetic configuration to influence magnetization dynamics. In this paper, we present an alternative approach to tunable magnonic systems. We studied theoretically and numerically a magnonic crystal induced within a uniform magnetic layer by a periodic magnetic field pattern created by the sequence of superconducting strips. We showed that the spin-wave spectrum can be tuned by the inhomogeneous stray field of the superconductor in response to a small uniform external magnetic field. Additionally, we demonstrated that modifying the width of superconducting strips and separation between them leads to the changes in the internal field which are unprecedented in conventional magnonic structures. The paper presents the results of semi-analytical calculations for realistic structures, which are verified by finite-element method computations. |
| 289. | Bivas Rana Journal of Applied Physics, 136 (15), pp. 150701, 2024, ISSN: 0021-8979. @article{10.1063/5.0233693, title = {Role of voltage-controlled magnetic anisotropy in the recent development of magnonics and spintronics}, author = {Bivas Rana}, url = {https://doi.org/10.1063/5.0233693}, doi = {10.1063/5.0233693}, issn = {0021-8979}, year = {2024}, date = {2024-10-16}, journal = {Journal of Applied Physics}, volume = {136}, number = {15}, pages = {150701}, abstract = {With significant recent progress in the thin film deposition and nanofabrication technology, a number of physical phenomena occur at the interfaces of magnetic thin films, and their heterostructures have been discovered. Consequently, the electric field-induced modulation of those interfacial properties mediated through spin–orbit coupling promises to develop magnetic material based smarter, faster, miniaturized, energy efficient spintronic devices. Among them, the electric field-induced modification of interfacial magnetic anisotropy, popularly termed as voltage-controlled magnetic anisotropy (VCMA), has attracted special attention because of its salient features. This article is devoted to reviewing the recent development of magnonics, which deals with collective precessional motion of ordered magnetic spins, i.e., spin waves (SWs), and skyrmions with chiral spin textures, with VCMA, including the perspectives of this research field. Starting with a broad introduction, the key features of VCMA and its advantages over other electric field-induced methods are highlighted. These are followed by describing the state-of-the-art of VCMA, and various other direct and indirect electric field-induced methods for magnetization reversal; controlling skyrmion dynamics; excitation, manipulation, and channeling of SWs; and tailoring magnonic bands. The critical challenges, their possible solutions, and future perspectives of this field are thoroughly discussed throughout the article.}, keywords = {}, pubstate = {published}, tppubtype = {article} } With significant recent progress in the thin film deposition and nanofabrication technology, a number of physical phenomena occur at the interfaces of magnetic thin films, and their heterostructures have been discovered. Consequently, the electric field-induced modulation of those interfacial properties mediated through spin–orbit coupling promises to develop magnetic material based smarter, faster, miniaturized, energy efficient spintronic devices. Among them, the electric field-induced modification of interfacial magnetic anisotropy, popularly termed as voltage-controlled magnetic anisotropy (VCMA), has attracted special attention because of its salient features. This article is devoted to reviewing the recent development of magnonics, which deals with collective precessional motion of ordered magnetic spins, i.e., spin waves (SWs), and skyrmions with chiral spin textures, with VCMA, including the perspectives of this research field. Starting with a broad introduction, the key features of VCMA and its advantages over other electric field-induced methods are highlighted. These are followed by describing the state-of-the-art of VCMA, and various other direct and indirect electric field-induced methods for magnetization reversal; controlling skyrmion dynamics; excitation, manipulation, and channeling of SWs; and tailoring magnonic bands. The critical challenges, their possible solutions, and future perspectives of this field are thoroughly discussed throughout the article. |
| 288. | Izabella Wojciechowska, Anna Dyrdał Intrinsic anomalous, spin and valley Hall effects in ’ex-so-tic’ van-der-Waals structures Scientific Reports, 14 , pp. 23808, 2024. @article{Wojciechowska2024, title = {Intrinsic anomalous, spin and valley Hall effects in ’ex-so-tic’ van-der-Waals structures}, author = {Izabella Wojciechowska and Anna Dyrdał }, url = {https://doi.org/10.1038/s41598-024-74596-x}, doi = {10.1038/s41598-024-74596-x}, year = {2024}, date = {2024-10-11}, journal = {Scientific Reports}, volume = {14}, pages = {23808}, abstract = {We consider the anomalous, spin, valley, and valley spin Hall effects in a pristine graphene-based van-der-Waals (vdW) heterostructure consisting of a bilayer graphene (BLG) sandwiched between a semiconducting van-der-Waals material with strong spin-orbit coupling (e.g., WS2) and a ferromagnetic insulating vdW material (e.g. Cr2Ge2Te2). Due to the exchange proximity effect from one side and spin-orbit proximity effect from the other side of graphene, such a structure is referred to as graphene based ’ex-so-tic’ structure. First, we derive an effective Hamiltonian describing the low-energy states of the structure. Then, using the Green’s function formalism, we obtain analytical results for the Hall conductivities as a function of the Fermi energy and gate voltage. For specific values of these parameters, we find a quantized valley Hall conductivity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We consider the anomalous, spin, valley, and valley spin Hall effects in a pristine graphene-based van-der-Waals (vdW) heterostructure consisting of a bilayer graphene (BLG) sandwiched between a semiconducting van-der-Waals material with strong spin-orbit coupling (e.g., WS2) and a ferromagnetic insulating vdW material (e.g. Cr2Ge2Te2). Due to the exchange proximity effect from one side and spin-orbit proximity effect from the other side of graphene, such a structure is referred to as graphene based ’ex-so-tic’ structure. First, we derive an effective Hamiltonian describing the low-energy states of the structure. Then, using the Green’s function formalism, we obtain analytical results for the Hall conductivities as a function of the Fermi energy and gate voltage. For specific values of these parameters, we find a quantized valley Hall conductivity. |
| 287. | Peter Zalom, Kacper Wrześniewski, Tomáš Novotný, Ireneusz Weymann Double quantum dot Andreev molecules: Phase diagrams and critical evaluation of effective models Physical Review B, 110 , pp. 134506, 2024. @article{Zalom2024, title = {Double quantum dot Andreev molecules: Phase diagrams and critical evaluation of effective models}, author = {Peter Zalom and Kacper Wrześniewski and Tomáš Novotný and Ireneusz Weymann}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.110.134506}, doi = {10.1103/PhysRevB.110.134506}, year = {2024}, date = {2024-10-07}, journal = {Physical Review B}, volume = {110}, pages = {134506}, abstract = {This paper systematically investigates the phase diagram of a parallel double-quantum-dot Andreev molecule, where the two quantum dots are coupled to a common superconducting lead. Using the numerical renormalization group method, we map out the evolution of the ground state across a wide parameter space of level detunings, size of the superconducting gap, lead couplings, and interdot coupling strength. The intricate phase diagrams feature singlet, doublet, and a relatively uncommon triplet ground states, with the latter being a distinct signature of strong lead-mediated interactions between the quantum dots. We benchmark the applicability of simplified effective models, including the atomic limit and zero-bandwidth approximations, in capturing the complex behavior of this parallel configuration. Our analysis reveals severe limitations of these models, underscoring the necessity for maximal caution when extrapolating beyond their tested validity. In particular, all effective models except for the extended version of the zero-bandwidth approximation failed in reproducing the triplet ground state and made several false predictions. These findings provide crucial insights for interpreting experimental observations and designing superconducting devices based on quantum-dot architectures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper systematically investigates the phase diagram of a parallel double-quantum-dot Andreev molecule, where the two quantum dots are coupled to a common superconducting lead. Using the numerical renormalization group method, we map out the evolution of the ground state across a wide parameter space of level detunings, size of the superconducting gap, lead couplings, and interdot coupling strength. The intricate phase diagrams feature singlet, doublet, and a relatively uncommon triplet ground states, with the latter being a distinct signature of strong lead-mediated interactions between the quantum dots. We benchmark the applicability of simplified effective models, including the atomic limit and zero-bandwidth approximations, in capturing the complex behavior of this parallel configuration. Our analysis reveals severe limitations of these models, underscoring the necessity for maximal caution when extrapolating beyond their tested validity. In particular, all effective models except for the extended version of the zero-bandwidth approximation failed in reproducing the triplet ground state and made several false predictions. These findings provide crucial insights for interpreting experimental observations and designing superconducting devices based on quantum-dot architectures. |
| 286. | Piotr Graczyk, Maria Pugaczowa-Michalska, Maciej Krawczyk Generation of femtosecond spin-polarized current pulses at Fe/MgO interface by quasi-static voltage Physica E: Low-dimensional Systems and Nanostructures, 165 , pp. 116120, 2024, ISSN: 1386-9477. @article{GRACZYK2025116120, title = {Generation of femtosecond spin-polarized current pulses at Fe/MgO interface by quasi-static voltage}, author = {Piotr Graczyk and Maria Pugaczowa-Michalska and Maciej Krawczyk}, url = {https://www.sciencedirect.com/science/article/pii/S1386947724002248}, doi = {https://doi.org/10.1016/j.physe.2024.116120}, issn = {1386-9477}, year = {2024}, date = {2024-10-03}, journal = {Physica E: Low-dimensional Systems and Nanostructures}, volume = {165}, pages = {116120}, abstract = {The generation of short spin-current pulses is essential for fast spintronic devices. So far, spin current pulses are generated by femtosecond laser pulses which drive spins from a ferromagnetic metal layer. However, the need for miniaturization, simplicity and energy efficiency favour electric-field control of spintronic devices over optic or thermal control. Here, we combine ab initio calculations of electronic density of states at MgO/Fe interface with continuous model for charge transport to investigate the dynamics of the spin-dependent potential. We demonstrate that the voltage-driven instability of the electronic band structure due to the electronic resonant states at the Fe/MgO interface results in the generation of the femtosecond spin-polarized current pulse with the spin polarization up to P=7 00 % that propagates from the interface to the bulk. The dynamics of the current pulses driven by the Stoner instability depends neither on the dielectric relaxation time nor on the details of how the instability is achieved by changing the voltage, i.e. as long as the voltage changes are slow (quasi-static) with respect to the time determined by the spin diffusion constant, being of the order of fs. The presence of the instability can be detected by THz time-domain spectroscopy or pump-probe techniques.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The generation of short spin-current pulses is essential for fast spintronic devices. So far, spin current pulses are generated by femtosecond laser pulses which drive spins from a ferromagnetic metal layer. However, the need for miniaturization, simplicity and energy efficiency favour electric-field control of spintronic devices over optic or thermal control. Here, we combine ab initio calculations of electronic density of states at MgO/Fe interface with continuous model for charge transport to investigate the dynamics of the spin-dependent potential. We demonstrate that the voltage-driven instability of the electronic band structure due to the electronic resonant states at the Fe/MgO interface results in the generation of the femtosecond spin-polarized current pulse with the spin polarization up to P=7 00 % that propagates from the interface to the bulk. The dynamics of the current pulses driven by the Stoner instability depends neither on the dielectric relaxation time nor on the details of how the instability is achieved by changing the voltage, i.e. as long as the voltage changes are slow (quasi-static) with respect to the time determined by the spin diffusion constant, being of the order of fs. The presence of the instability can be detected by THz time-domain spectroscopy or pump-probe techniques. |
| 285. | Sławomir Mamica Scientific Reports, 14 (1), pp. 22966, 2024, ISSN: 2045-2322. @article{mamica_spin-wave_2024, title = {Spin-wave mode coupling in the presence of the demagnetizing field in cobalt-permalloy magnonic crystals}, author = {Sławomir Mamica}, url = {https://www.nature.com/articles/s41598-024-74923-2}, doi = {10.1038/s41598-024-74923-2}, issn = {2045-2322}, year = {2024}, date = {2024-10-03}, urldate = {2024-10-11}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {22966}, abstract = {We present the results of studies on the non-uniform frequency shift of spin wave spectrum in a two-dimensional magnonic crystal of cobalt/permalloy under the influence of external magnetic field changes. We investigate the phenomenon of coupling of modes and, as a consequence, their hybridization. By taking advantage of the fact that compressing the crystal structure along the direction of the external magnetic field leads to an enhancement of the demagnetizing field, we analyse its effect on the frequency shift of individual modes depending on their concentration in Co. We show that the consequence of this enhancement is a shift in the coupling of modes towards higher magnetic fields. This provides a potential opportunity to design which pairs of modes and in what range of fields hybridization will occur.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present the results of studies on the non-uniform frequency shift of spin wave spectrum in a two-dimensional magnonic crystal of cobalt/permalloy under the influence of external magnetic field changes. We investigate the phenomenon of coupling of modes and, as a consequence, their hybridization. By taking advantage of the fact that compressing the crystal structure along the direction of the external magnetic field leads to an enhancement of the demagnetizing field, we analyse its effect on the frequency shift of individual modes depending on their concentration in Co. We show that the consequence of this enhancement is a shift in the coupling of modes towards higher magnetic fields. This provides a potential opportunity to design which pairs of modes and in what range of fields hybridization will occur. |
| 284. | I. Inoue, V. Tkachenko, Y. Kubota, F. Dorchies, T. Hara, H. Höppner, Y. Inubushi, Konrad J. Kapcia, H. J. Lee, V. Lipp, P. Martinez, Eiji Nishibori, Taito Osaka, S. Toleikis, J. Yamada, Makina Yabashi, Beata Ziaja, P. Heimann Interplay of thermal and nonthermal effects in x-ray-induced ultrafast melting Phys. Rev. B, 110 , pp. L100102 , 2024. @article{Inoue2024, title = {Interplay of thermal and nonthermal effects in x-ray-induced ultrafast melting}, author = {I. Inoue and V. Tkachenko and Y. Kubota and F. Dorchies and T. Hara and H. Höppner and Y. Inubushi and Konrad J. Kapcia and H. J. Lee and V. Lipp and P. Martinez and Eiji Nishibori and Taito Osaka and S. Toleikis and J. Yamada and Makina Yabashi and Beata Ziaja and P. Heimann}, doi = {10.1103/PhysRevB.110.L100102}, year = {2024}, date = {2024-09-27}, journal = {Phys. Rev. B}, volume = {110}, pages = {L100102 }, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 283. | D Panda, K K Behera, S Madhur, Bivas Rana, A Gloskovskii, Y Otani, A Barman, I Sarkar Phys. Rev. B, 110 , pp. 094424, 2024. @article{PhysRevB.110.094424, title = {Role of the nonmagnetic underlayer in controlling the electronic structure of ferromagnet/nonmagnetic-metal heterostructures}, author = {D Panda and K K Behera and S Madhur and Bivas Rana and A Gloskovskii and Y Otani and A Barman and I Sarkar}, url = {https://link.aps.org/doi/10.1103/PhysRevB.110.094424}, doi = {10.1103/PhysRevB.110.094424}, year = {2024}, date = {2024-09-18}, journal = {Phys. Rev. B}, volume = {110}, pages = {094424}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 282. | Wojciech Rudziński, Józef Barnaś, Anna Dyrdał Journal of Magnetism and Magnetic Materials, 606 , pp. 172321, 2024. @article{Rudzinski2024b, title = {Spin waves in antiferromagnetically coupled bilayers of transition-metal dichalcogenides with Dzyaloshinskii–Moriya interaction}, author = {Wojciech Rudziński and Józef Barnaś and Anna Dyrdał}, url = {https://doi.org/10.1016/j.jmmm.2024.172321}, doi = {10.1016/j.jmmm.2024.172321}, year = {2024}, date = {2024-09-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {606}, pages = {172321}, abstract = {In this paper we analyse quantized spin waves (also referred to as magnons) in bilayers of two-dimensional van der Waals materials, like Vanadium-based dichalcogenides, VX2 (X = S, Se, Te) and other materials of similar symmetry. We assume that the materials exhibit Dzyaloshinskii–Moriya interaction and in-plane easy-axis magnetic anisotropy due to symmetry breaking induced externally (e.g. by strain, gate voltage, proximity effects to an appropriate substrate/oberlayer, etc.). The considerations are limited to a collinear spin ground state, stabilized by a sufficiently strong in-plane magnetic anisotropy. The theoretical analysis is performed within the general spin wave theory based on the Holstein–Primakoff–Bogoliubov transformation. Accordingly, the description takes into account quantum antiferromagnetic fluctuations. However, it is limited to linear spinwave modes. The Dzyaloshinskii–Moriya interaction is shown to modify the spin wave spectrum of the bilayers, making its low energy part qualitatively similar to the electronic spectrum of the Rashba spin–orbit model.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper we analyse quantized spin waves (also referred to as magnons) in bilayers of two-dimensional van der Waals materials, like Vanadium-based dichalcogenides, VX2 (X = S, Se, Te) and other materials of similar symmetry. We assume that the materials exhibit Dzyaloshinskii–Moriya interaction and in-plane easy-axis magnetic anisotropy due to symmetry breaking induced externally (e.g. by strain, gate voltage, proximity effects to an appropriate substrate/oberlayer, etc.). The considerations are limited to a collinear spin ground state, stabilized by a sufficiently strong in-plane magnetic anisotropy. The theoretical analysis is performed within the general spin wave theory based on the Holstein–Primakoff–Bogoliubov transformation. Accordingly, the description takes into account quantum antiferromagnetic fluctuations. However, it is limited to linear spinwave modes. The Dzyaloshinskii–Moriya interaction is shown to modify the spin wave spectrum of the bilayers, making its low energy part qualitatively similar to the electronic spectrum of the Rashba spin–orbit model. |
| 281. | Ievgen I Arkhipov, Fabrizio Minganti, Adam Miranowicz, Sahin K Özdemir, Franco Nori Restoring Adiabatic State Transfer in Time-Modulated Non-Hermitian Systems Phys. Rev. Lett., 133 , pp. 113802, 2024. @article{Arkhipov24prl, title = {Restoring Adiabatic State Transfer in Time-Modulated Non-Hermitian Systems}, author = {Ievgen I Arkhipov and Fabrizio Minganti and Adam Miranowicz and Sahin K Özdemir and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.133.113802}, doi = {10.1103/PhysRevLett.133.113802}, year = {2024}, date = {2024-09-01}, journal = {Phys. Rev. Lett.}, volume = {133}, pages = {113802}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 280. | Shashank Shekhar, Sławomir Mielcarek, Y Otani, Bivas Rana, Aleksandra Trzaskowska Effect of the underlayer on the elastic parameters of the CoFeB/MgO heterostructures Scientific Reports, 14 (1), pp. 20259, 2024, ISSN: 2045-2322. @article{shekhar_effect_2024, title = {Effect of the underlayer on the elastic parameters of the CoFeB/MgO heterostructures}, author = {Shashank Shekhar and Sławomir Mielcarek and Y Otani and Bivas Rana and Aleksandra Trzaskowska}, url = {https://www.nature.com/articles/s41598-024-71110-1}, doi = {10.1038/s41598-024-71110-1}, issn = {2045-2322}, year = {2024}, date = {2024-08-31}, urldate = {2024-09-12}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {20259}, abstract = {We investigated the thermally induced surface acoustic waves in CoFeB/MgO heterostructures with different underlayer materials. Our results show a direct correlation between the density and elastic parameters of the underlayer materials and the surface phonon dispersion. Using finite element method-based simulations, we calculate the effective elastic parameters (such as elastic tensor, Young’s modulus, and Poisson’s ratio) for multilayers with different underlayer materials. The simulation results, either considering the elastic parameters of individual layers or considering the effective elastic parameters of whole stacks, exhibit good agreement with the experimental data. This study will help us deepen our understanding of phonon properties and their interactions with other quasiparticles or magnetic textures with the help of these estimated elastic properties.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigated the thermally induced surface acoustic waves in CoFeB/MgO heterostructures with different underlayer materials. Our results show a direct correlation between the density and elastic parameters of the underlayer materials and the surface phonon dispersion. Using finite element method-based simulations, we calculate the effective elastic parameters (such as elastic tensor, Young’s modulus, and Poisson’s ratio) for multilayers with different underlayer materials. The simulation results, either considering the elastic parameters of individual layers or considering the effective elastic parameters of whole stacks, exhibit good agreement with the experimental data. This study will help us deepen our understanding of phonon properties and their interactions with other quasiparticles or magnetic textures with the help of these estimated elastic properties. |
| 279. | Amir N. Zarezad, Alireza Qaiumzadeh, Józef Barnaś, Anna Dyrdał Topological charge and spin Hall effects due to skyrmions in canted antiferromagnets Physical Review B, 110 (5), pp. 054431, 2024. @article{Zarezad2024b, title = {Topological charge and spin Hall effects due to skyrmions in canted antiferromagnets}, author = {Amir N. Zarezad and Alireza Qaiumzadeh and Józef Barnaś and Anna Dyrdał }, url = {https://doi.org/10.1103/PhysRevB.110.054431}, doi = {10.1103/PhysRevB.110.054431}, year = {2024}, date = {2024-08-20}, journal = {Physical Review B}, volume = {110}, number = {5}, pages = {054431}, abstract = {The topological charge Hall effect (TCHE) and the topological spin Hall effect (TSHE), arising from ferromagnetic (FM) and antiferromagnetic (AFM) skyrmions, respectively, can be elucidated through the emergence of spin-dependent Berry gauge fields that affect the adiabatic flow of electrons within the skyrmion texture. TCHE is absent in systems with parity-time (PT) symmetry, such as collinear AFM systems. In this paper, we theoretically study TCHE and TSHE in a canted antiferromagnet within the diffusive transport regime. Spin canting or weak ferromagnetism in canted AFMs, which break the PT symmetry, may arise, e.g., from strong homogeneous Dzyaloshinskii-Moriya interactions. Using a semiclassical Boltzmann approach, we obtain diffusion equations for the spin and charge accumulations in the presence of finite spin flip and spin-dependent momentum relaxation times. We show that the weak ferromagnetic moment stemming from spin canting and the subsequent breaking of PT symmetry, results in the emergence of both finite TCHE and TSHE in AFM systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The topological charge Hall effect (TCHE) and the topological spin Hall effect (TSHE), arising from ferromagnetic (FM) and antiferromagnetic (AFM) skyrmions, respectively, can be elucidated through the emergence of spin-dependent Berry gauge fields that affect the adiabatic flow of electrons within the skyrmion texture. TCHE is absent in systems with parity-time (PT) symmetry, such as collinear AFM systems. In this paper, we theoretically study TCHE and TSHE in a canted antiferromagnet within the diffusive transport regime. Spin canting or weak ferromagnetism in canted AFMs, which break the PT symmetry, may arise, e.g., from strong homogeneous Dzyaloshinskii-Moriya interactions. Using a semiclassical Boltzmann approach, we obtain diffusion equations for the spin and charge accumulations in the presence of finite spin flip and spin-dependent momentum relaxation times. We show that the weak ferromagnetic moment stemming from spin canting and the subsequent breaking of PT symmetry, results in the emergence of both finite TCHE and TSHE in AFM systems. |
| 278. | Josef Kadlec, Karol Bartkiewicz, Antonín Černoch, Karel Lemr, Adam Miranowicz Experimental relative entanglement potentials of single-photon states Phys. Rev. A, 110 , pp. 023720, 2024. @article{PhysRevA.110.023720, title = {Experimental relative entanglement potentials of single-photon states}, author = {Josef Kadlec and Karol Bartkiewicz and Antonín Černoch and Karel Lemr and Adam Miranowicz}, url = {https://link.aps.org/doi/10.1103/PhysRevA.110.023720}, doi = {10.1103/PhysRevA.110.023720}, year = {2024}, date = {2024-08-01}, journal = {Phys. Rev. A}, volume = {110}, pages = {023720}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 277. | Riya Mehta, Bivas Rana, Susmita Saha Magnetization dynamics in quasiperiodic magnonic crystals Journal of Physics: Condensed Matter, 36 (44), pp. 443003, 2024. @article{Mehta_2024, title = {Magnetization dynamics in quasiperiodic magnonic crystals}, author = {Riya Mehta and Bivas Rana and Susmita Saha}, url = {https://dx.doi.org/10.1088/1361-648X/ad5ee8}, doi = {10.1088/1361-648X/ad5ee8}, year = {2024}, date = {2024-08-01}, journal = {Journal of Physics: Condensed Matter}, volume = {36}, number = {44}, pages = {443003}, publisher = {IOP Publishing}, abstract = {Quasiperiodic magnonic crystals, in contrast to their periodic counterparts, lack strict periodicity which gives rise to complex and localised spin wave spectra characterized by numerous band gaps and fractal features. Despite their intrinsic structural complexity, quasiperiodic nature of these magnonic crystals enables better tunability of spin wave spectra over their periodic counterparts and therefore holds promise for the applications in reprogrammable magnonic devices. In this article, we provide an overview of magnetization reversal and precessional magnetization dynamics studied so far in various quasiperiodic magnonic crystals, illustrating how their quasiperiodic nature gives rise to tailored band structure, enabling unparalleled control over spin waves. The review is concluded by highlighting the possible potential applications of these quasiperiodic magnonic crystals, exploring potential avenues for future exploration followed by a brief summary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Quasiperiodic magnonic crystals, in contrast to their periodic counterparts, lack strict periodicity which gives rise to complex and localised spin wave spectra characterized by numerous band gaps and fractal features. Despite their intrinsic structural complexity, quasiperiodic nature of these magnonic crystals enables better tunability of spin wave spectra over their periodic counterparts and therefore holds promise for the applications in reprogrammable magnonic devices. In this article, we provide an overview of magnetization reversal and precessional magnetization dynamics studied so far in various quasiperiodic magnonic crystals, illustrating how their quasiperiodic nature gives rise to tailored band structure, enabling unparalleled control over spin waves. The review is concluded by highlighting the possible potential applications of these quasiperiodic magnonic crystals, exploring potential avenues for future exploration followed by a brief summary. |
| 276. | Piotr Majek, Ireneusz Weymann Spin-selective transport in a correlated double quantum dot-Majorana wire system Scientific Reports, 14 , pp. 17762, 2024. @article{Majek2024b, title = {Spin-selective transport in a correlated double quantum dot-Majorana wire system}, author = {Piotr Majek and Ireneusz Weymann}, url = {https://www.nature.com/articles/s41598-024-66478-z}, doi = {10.1038/s41598-024-66478-z}, year = {2024}, date = {2024-08-01}, journal = {Scientific Reports}, volume = {14}, pages = {17762}, abstract = {In this work we investigate the spin-dependent transport through a double quantum dot embedded in a ferromagnetic tunnel junction and side attached to a topological superconducting nanowire hosting Majorana zero-energy modes. We focus on the transport regime when the Majorana mode leaks into the double quantum dot competing with the two-stage Kondo effect and the ferromagnetic-contact-induced exchange field. In particular, we determine the system’s spectral properties and analyze the temperature dependence of the spin-resolved linear conductance by means of the numerical renormalization group method. Our study reveals unique signatures of the interplay between the spin-resolved tunneling, the Kondo effect and the Majorana modes, which are visible in the transport characteristics. In particular, we uncover a competing character of the coupling to topological superconductor and that to ferromagnetic leads, which can be observed already for very low spin polarization of the electrodes. This is signaled by an almost complete quenching of the conductance in one of the spin channels which is revealed through perfect conductance spin polarization. Moreover, we show that the conductance spin polarization can change sign depending on the magnitude of spin imbalance in the leads and strength of interaction with topological wire. Thus, our work demonstrates that even minuscule spin polarization of tunneling processes can have large impact on the transport properties of the system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work we investigate the spin-dependent transport through a double quantum dot embedded in a ferromagnetic tunnel junction and side attached to a topological superconducting nanowire hosting Majorana zero-energy modes. We focus on the transport regime when the Majorana mode leaks into the double quantum dot competing with the two-stage Kondo effect and the ferromagnetic-contact-induced exchange field. In particular, we determine the system’s spectral properties and analyze the temperature dependence of the spin-resolved linear conductance by means of the numerical renormalization group method. Our study reveals unique signatures of the interplay between the spin-resolved tunneling, the Kondo effect and the Majorana modes, which are visible in the transport characteristics. In particular, we uncover a competing character of the coupling to topological superconductor and that to ferromagnetic leads, which can be observed already for very low spin polarization of the electrodes. This is signaled by an almost complete quenching of the conductance in one of the spin channels which is revealed through perfect conductance spin polarization. Moreover, we show that the conductance spin polarization can change sign depending on the magnitude of spin imbalance in the leads and strength of interaction with topological wire. Thus, our work demonstrates that even minuscule spin polarization of tunneling processes can have large impact on the transport properties of the system. |
| 275. | 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. |
| 274. | 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. |
| 273. | Vojtiěch Trávníček, Jan Roik, Karol Bartkiewicz, Antonín Černoch, Paweł Horodecki, Karel Lemr Sensitivity versus selectivity in entanglement detection via collective witnesses Phys. Rev. Res., 6 , pp. 033056, 2024. @article{PhysRevResearch.6.033056, title = {Sensitivity versus selectivity in entanglement detection via collective witnesses}, author = {Vojtiěch Trávníček and Jan Roik and Karol Bartkiewicz and Antonín Černoch and Paweł Horodecki and Karel Lemr}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.6.033056}, doi = {10.1103/PhysRevResearch.6.033056}, year = {2024}, date = {2024-07-01}, journal = {Phys. Rev. Res.}, volume = {6}, pages = {033056}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |