Yusuke Kato
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Yusuke Kato has a total of 44 co-authors. Here are the top co-authors by number of shared publications:
- Shohei Watabe
Tokyo University of Science
4 shared publications - Chun Kit Chung
Department of Physics The University of Tokyo 113-0033 Tokyo Japan
3 shared publications - Hiroto Adachi
Okayama University
3 shared publications - Noriyuki Kurosawa
Department of Basic Science The University of Tokyo 153-8902 Meguro Tokyo Japan
3 shared publications - Yuta Suzuki
Institute of Science Tokyo
3 shared publications - Akihiro Tanaka
National Institute for Materials Science 1-1 Namiki 305-0044 Ibaraki Tsukuba Japan
2 shared publications
Latest Publications
- 31 August 2026
- Published by American Physical Society (APS) in Physical Review B
- Vol. 114 (8)
Dynamics of topological defects in type-II superconductors in the presence of gradients of temperature and spin density
- 31 August 2026
- Published by American Physical Society (APS) in Physical Review B
- Vol. 114 (8)
Dynamics of topological defects in type-II superconductors in the presence of gradients of temperature and spin density
- 6 April 2026
- Published by American Physical Society (APS) in Physical Review B
- Vol. 113 (15)
Chirality-dependent spin polarization in metals: linear and quadratic responses
- 6 April 2026
- Published by American Physical Society (APS) in Physical Review B
- Vol. 113 (15)
Chirality-dependent spin polarization in metals: linear and quadratic responses
- Open Access
- 27 October 2025
- Published by American Physical Society (APS) in Physical Review Research
- Vol. 7 (4)
Systematic construction of asymptotic quantum many-body scar states and their relation to supersymmetric quantum mechanics
We develop a systematic method for constructing asymptotic quantum many-body scar (AQMBS) states. While AQMBS states are closely related to quantum many-body scar (QMBS) states, they exhibit key differences. Unlike QMBS states, AQMBS states are not energy eigenstates of the Hamiltonian, making their construction more challenging. We demonstrate that, under appropriate conditions, AQMBS states can be obtained as low-lying gapless excited states of a parent Hamiltonian, which has a QMBS state as its ground state. Furthermore, our formalism reveals a connection between QMBS and supersymmetric (SUSY) quantum mechanics. The QMBS state can be interpreted as a SUSY-unbroken ground state.
- 27 October 2025
- Published by American Physical Society (APS) in Physical Review Research
- Vol. 7 (4)
Open AccessSystematic construction of asymptotic quantum many-body scar states and their relation to supersymmetric quantum mechanics
We develop a systematic method for constructing asymptotic quantum many-body scar (AQMBS) states. While AQMBS states are closely related to quantum many-body scar (QMBS) states, they exhibit key differences. Unlike QMBS states, AQMBS states are not energy eigenstates of the Hamiltonian, making their construction more challenging. We demonstrate that, under appropriate conditions, AQMBS states can be obtained as low-lying gapless excited states of a parent Hamiltonian, which has a QMBS state as its ground state. Furthermore, our formalism reveals a connection between QMBS and supersymmetric (SUSY) quantum mechanics. The QMBS state can be interpreted as a SUSY-unbroken ground state.
- 6 September 2024
- Published by American Physical Society (APS) in Physical Review B
- Vol. 110 (10)
Anisotropy-induced spin parity effects
- 6 September 2024
- Published by American Physical Society (APS) in Physical Review B
- Vol. 110 (10)
Anisotropy-induced spin parity effects
- 27 March 2023
- Published by American Physical Society (APS) in Physical Review B
- Vol. 107 (11) , 115305
Spin relaxation, diffusion, and Edelstein effect in chiral metal surface
We study electron spin transport at the spin-splitting surface of chiral-crystalline-structured metals and the Edelstein effect at the interface, by using the Boltzmann transport equation beyond the relaxation time approximation. We first define spin relaxation time and spin diffusion length for two-dimensional systems with anisotropic spin-orbit coupling through the spectrum of the integral kernel in the collision integral. We then explicitly take account of the interface between the chiral metal and a nonmagnetic metal with finite thickness. For this composite system, we derive analytical expressions for efficiency of the charge current–spin current interconversion as well as other coefficients found in the Edelstein effect. We also develop the Onsager reciprocity in the Edelstein effect along with experiments so that it relates local input and output, which are respectively defined in the regions separated by the interface. We finally provide a transfer matrix corresponding to the Edelstein effect through the interface, with which we can easily represent the Onsager reciprocity as well as the charge-spin conversion efficiencies we have obtained. We confirm the validity of the Boltzmann transport equation in the present system starting from the Keldysh formalism in supplemental material. Our formulation also applies to the Rashba model and other spin-splitting systems.
- 27 March 2023
- Published by American Physical Society (APS) in Physical Review B
- Vol. 107 (11) , 115305
Spin relaxation, diffusion, and Edelstein effect in chiral metal surface
We study electron spin transport at the spin-splitting surface of chiral-crystalline-structured metals and the Edelstein effect at the interface, by using the Boltzmann transport equation beyond the relaxation time approximation. We first define spin relaxation time and spin diffusion length for two-dimensional systems with anisotropic spin-orbit coupling through the spectrum of the integral kernel in the collision integral. We then explicitly take account of the interface between the chiral metal and a nonmagnetic metal with finite thickness. For this composite system, we derive analytical expressions for efficiency of the charge current–spin current interconversion as well as other coefficients found in the Edelstein effect. We also develop the Onsager reciprocity in the Edelstein effect along with experiments so that it relates local input and output, which are respectively defined in the regions separated by the interface. We finally provide a transfer matrix corresponding to the Edelstein effect through the interface, with which we can easily represent the Onsager reciprocity as well as the charge-spin conversion efficiencies we have obtained. We confirm the validity of the Boltzmann transport equation in the present system starting from the Keldysh formalism in supplemental material. Our formulation also applies to the Rashba model and other spin-splitting systems.
- 4 January 2023
- Published by American Physical Society (APS) in Physical Review B
- Vol. 107 (2) , 024403
Spin parity effects in a monoaxial chiral ferromagnetic chain
While spin parity effects, physics crucially depending on whether the spin quantum number is half-odd integral or integral, have for decades been a source of new developments for the quantum physics of antiferromagnetic spin chains, the investigation into their possible ferromagnetic counterparts has remained largely unchartered, especially in the fully quantum (as opposed to the semiclassical) regime. Here we present such studies for monoaxial chiral ferromagnetic spin chains. We start by examining magnetization curves for finite-sized systems, where a magnetic field is applied perpendicular to the helical axis. For half-odd integer , the curves feature discontinuous jumps identified as a series of level crossings, each accompanied by a shift of the crystal momentum by an amount of . The corresponding curves for integer valued are continuous and exhibit crossover processes. For the latter case, throughout. These characteristics are observed numerically when the strength of the Dzyaloshinskii-Moriya interaction (DMI) is comparable to or larger than that of the ferromagnetic exchange interaction . Solitons are known to be responsible for stepwise changes seen in magnetization curves in the classical limit. These findings therefore prompt us to revise the notion of a soliton, for arbitrary , into a quantum mechanical entity. To unravel this phenomenon at the fully quantum level as is appropriate to spin chains with small , we examine in detail special limiting Hamiltonians amenable to rigorous analysis, consisting of only the DMI and the Zeeman energy. Dubbed the model (for ) and the projected () model (for general ), they have a set of conserved quantities, each of which is the number of solitons of a specific integer-valued height (as measured in the basis), which ranges from 1 to . We discuss how to determine the exact crystal momentum of the lowest-energy state belonging to a sector with a given set of the soliton numbers. Combined with energetic considerations, this information enables us to reproduce the spin parity effect in the magnetization curves. Finally, we show that the ground states of the special models have substantial numerical overlap with those for generic systems with a finite exchange interaction, suggesting the same physics to be valid there as well.- 4 January 2023
- Published by American Physical Society (APS) in Physical Review B
- Vol. 107 (2) , 024403
Spin parity effects in a monoaxial chiral ferromagnetic chain
While spin parity effects, physics crucially depending on whether the spin quantum number is half-odd integral or integral, have for decades been a source of new developments for the quantum physics of antiferromagnetic spin chains, the investigation into their possible ferromagnetic counterparts has remained largely unchartered, especially in the fully quantum (as opposed to the semiclassical) regime. Here we present such studies for monoaxial chiral ferromagnetic spin chains. We start by examining magnetization curves for finite-sized systems, where a magnetic field is applied perpendicular to the helical axis. For half-odd integer , the curves feature discontinuous jumps identified as a series of level crossings, each accompanied by a shift of the crystal momentum by an amount of . The corresponding curves for integer valued are continuous and exhibit crossover processes. For the latter case, throughout. These characteristics are observed numerically when the strength of the Dzyaloshinskii-Moriya interaction (DMI) is comparable to or larger than that of the ferromagnetic exchange interaction . Solitons are known to be responsible for stepwise changes seen in magnetization curves in the classical limit. These findings therefore prompt us to revise the notion of a soliton, for arbitrary , into a quantum mechanical entity. To unravel this phenomenon at the fully quantum level as is appropriate to spin chains with small , we examine in detail special limiting Hamiltonians amenable to rigorous analysis, consisting of only the DMI and the Zeeman energy. Dubbed the model (for ) and the projected () model (for general ), they have a set of conserved quantities, each of which is the number of solitons of a specific integer-valued height (as measured in the basis), which ranges from 1 to . We discuss how to determine the exact crystal momentum of the lowest-energy state belonging to a sector with a given set of the soliton numbers. Combined with energetic considerations, this information enables us to reproduce the spin parity effect in the magnetization curves. Finally, we show that the ground states of the special models have substantial numerical overlap with those for generic systems with a finite exchange interaction, suggesting the same physics to be valid there as well.- Open Access
Spin Relaxation, Diffusion and Edelstein Effect in Chiral Metal Surface
We study electron spin transport at spin-splitting surface of chiral-crystalline-structured metals and Edelstein effect at the interface, by using the Boltzmann transport equation beyond the relaxation time approximation. We first define spin relaxation time and spin diffusion length for two-dimensional systems with anisotropic spin--orbit coupling through the spectrum of the integral kernel in the collision integral. We then explicitly take account of the interface between the chiral metal and a nonmagnetic metal with finite thickness. For this composite system, we derive analytical expressions for efficiency of the charge current--spin current interconversion as well as other coefficients found in the Edelstein effect. We also develop the Onsager's reciprocity in the Edelstein effect along with experiments so that it relates local input and output, which are respectively defined in the regions separated by the interface. We finally provide a transfer matrix corresponding to the Edelstein effect through the interface, with which we can easily represent the Onsager's reciprocity as well as the charge--spin conversion efficiencies we have obtained. We confirm the validity of the Boltzmann transport equation in the present system starting from the Keldysh formalism in the supplemental material. Our formulation also applies to the Rashba model and other spin-splitting systems.
Open AccessSpin Relaxation, Diffusion and Edelstein Effect in Chiral Metal Surface
We study electron spin transport at spin-splitting surface of chiral-crystalline-structured metals and Edelstein effect at the interface, by using the Boltzmann transport equation beyond the relaxation time approximation. We first define spin relaxation time and spin diffusion length for two-dimensional systems with anisotropic spin--orbit coupling through the spectrum of the integral kernel in the collision integral. We then explicitly take account of the interface between the chiral metal and a nonmagnetic metal with finite thickness. For this composite system, we derive analytical expressions for efficiency of the charge current--spin current interconversion as well as other coefficients found in the Edelstein effect. We also develop the Onsager's reciprocity in the Edelstein effect along with experiments so that it relates local input and output, which are respectively defined in the regions separated by the interface. We finally provide a transfer matrix corresponding to the Edelstein effect through the interface, with which we can easily represent the Onsager's reciprocity as well as the charge--spin conversion efficiencies we have obtained. We confirm the validity of the Boltzmann transport equation in the present system starting from the Keldysh formalism in the supplemental material. Our formulation also applies to the Rashba model and other spin-splitting systems.