119 citations · 547 across the 23 of their papers we have counts for
25 papers
Density-matrix quantum kinetics of spin-mode crossover and ac Edelstein response in spin--orbit-coupled chiral metals
Shuntaro Sumita, Yusuke Kato
To clarify spin relaxation and precession across the weak-to-strong SOC crossover in chiral conductors, we formulate a density-matrix quantum kinetic theory for a three-dimensional…
Fluctuation-induced antiparallel spin polarization near the boundaries of chiral metals
Kosuke Yoshimi, Yusuke Kato, Yuta Suzuki +4
The spin response of chiral conductors to nonequilibrium electrical fluctuations remains largely unexplored. We develop a low-frequency semiclassical Boltzmann theory coupled to Ga…
Theory of Magnetic Excitations in the Heavy-Fermion Spin-Triplet Superconductor UTe
Koki Shimura, Shuntaro Sumita, Yusuke Kato
We study the dynamical spin response of UTe by using a mixed-dimensional periodic Anderson model. Within the BCS-RPA formalism, we examine how the -orbital character of the…
Two routes to quantum anomalous Hall states in altermagnets
Makoto Naka, Shuntaro Sumita, Yukitoshi Motome +1
We theoretically propose two possible routes to realizing quantum anomalous Hall states in altermagnetic materials. We consider a minimal square-lattice Hubbard model with antisymm…
Boundary condition for phonon distribution functions at a smooth crystal interface and interfacial angular momentum transfer
Yuta Suzuki, Shuntaro Sumita, Yusuke Kato
We theoretically elucidate the boundary conditions for phonon distribution functions of long-wavelength acoustic phonons at smooth crystal interfaces. We first derive boundary cond…
Phase-modulated superconductivity via altermagnetism
Shuntaro Sumita, Makoto Naka, Hitoshi Seo
Stimulated by recent interest in altermagnets, a novel class of antiferromagnets with macroscopic time-reversal symmetry breaking, we investigate the coexistence of altermagnetism…
Theory of phonon angular momentum transport across a smooth crystal interface
Yuta Suzuki, Shuntaro Sumita, Yusuke Kato
We theoretically elucidate the transfer of phonon angular momentum by acoustic modes across a smooth interface between crystals. We analyze this process, which is difficult to desc…
Chirality-dependent spin polarization in metals: linear and quadratic responses
Kosuke Yoshimi, Yusuke Kato, Yuta Suzuki +6
We study spin polarization induced by locally injected electric currents in a metal whose spin--orbit coupling reflects its structural chirality. We reveal both spin polarization i…
Anisotropy-induced spin parity effects
Shuntaro Sumita, Akihiro Tanaka, Yusuke Kato
Spin parity effects refer to those special situations where a dichotomy in the physical behavior of a system arises, solely depending on whether the relevant spin quantum number is…
Ideal Spin-Orbit-Free Dirac Semimetal and Diverse Topological Transitions in PrCoGa Family
Manabu Sato, Juba Bouaziz, Shuntaro Sumita +5
Topological semimetals, known for their intriguing properties arising from band degeneracies, have garnered significant attention. However, the discovery of a material realization…
Spin-orbit enabled unconventional Stoner magnetism
Yue Yu, Tatsuya Shishidou, Shuntaro Sumita +2
The Stoner instability remains a cornerstone for understanding metallic ferromagnets. This instability captures the interplay of Coulomb repulsion, Pauli exclusion, and two-fold fe…
Fulde-Ferrell-Larkin-Ovchinnikov state induced by antiferromagnetic order in -type organic conductors
Shuntaro Sumita, Makoto Naka, Hitoshi Seo
We theoretically investigate superconductivity under a spin-split band structure owing to a collinear-type antiferromagnetic order in quasi-two-dimensional organic compounds -(B…
Crystal-symmetry-protected gapless vortex-line phases in superconducting Dirac semimetals
Shingo Kobayashi, Shuntaro Sumita, Motoaki Hirayama +1
Vortex lines in superconducting Dirac semimetals realize crystal-symmetry-protected gapless vortex-line phases in which gapless excitations propagate inside a vortex line, in the p…
Supercurrent-Induced Weyl Superconductivity
Shuntaro Sumita, Kazuaki Takasan
We show that Weyl superconductivity can be induced by finite supercurrent in noncentrosymmetric spin-orbit-coupled superconductors with line nodes. We introduce a three-dimensional…
Supercurrent-induced topological phase transitions
Kazuaki Takasan, Shuntaro Sumita, Youichi Yanase
We show that finite current in superconductors can induce topological phase transitions, as a result of the deformation of the quasiparticle spectrum by a finite center-of-mass (CO…
Dirac lines and loop at the Fermi level in the Time-Reversal Symmetry Breaking Superconductor LaNiGa
Jackson R. Badger, Yundi Quan, Matthew C. Staab +12
Unconventional superconductors have Cooper pairs with lower symmetries than in conventional superconductors. In most unconventional superconductors, the additional symmetry breakin…
Superconductor/normal-metal/superconductor junction of topological superconductors revisited: Fractional Josephson current, fermion parity, and oscillating wavefunctions
Shuntaro Sumita, Akira Furusaki
The fractional Josephson effect is known to be a characteristic phenomenon of topological Josephson junctions hosting Majorana zero modes (MZMs), where the Josephson current has a…
Topological gapless points in superconductors: From the viewpoint of symmetry
Shuntaro Sumita, Youichi Yanase
Searching for topological insulators/superconductors is a central subject in recent condensed matter physics. As a theoretical aspect, various classification methods of symmetry-pr…
Superconductivity induced by fluctuations of momentum-based multipoles
Shuntaro Sumita, Youichi Yanase
Recent studies of unconventional superconductivity have focused on charge or spin fluctuation, instead of electron-phonon coupling, as an origin of attractive interaction between e…
Insulator-metal transition and topological superconductivity in UTe2 from a first-principles calculation
Jun Ishizuka, Shuntaro Sumita, Akito Daido +1
We theoretically study superconductivity in UTe, which is a recently-discovered strong candidate for an odd-parity spin-triplet superconductor. Theoretical studies for this com…
Classification of topological crystalline superconducting nodes on high-symmetry lines: Point nodes, line nodes, and Bogoliubov Fermi surfaces
Shuntaro Sumita, Takuya Nomoto, Ken Shiozaki +1
Recent development in exact classification of a superconducting gap has elucidated various unconventional gap structures, which have not been predicted by the classification of ord…
Unconventional superconducting gap structure protected by space group symmetry
Shuntaro Sumita, Youichi Yanase
Recent superconducting gap classifications based on space group symmetry have revealed nontrivial gap structures that were not shown by point group symmetry. First, we review a com…
Symmetry-protected line nodes and Majorana flat bands in nodal crystalline superconductors
Shingo Kobayashi, Shuntaro Sumita, Youichi Yanase +1
Line nodes in the superconducting gap are known to be a source of Majorana flat bands (MFBs) in time-reversal-invariant superconductors (SCs). Here, we extend this relation to all…
Multipole superconductivity in nonsymmorphic SrIrO
Shuntaro Sumita, Takuya Nomoto, Youichi Yanase
Discoveries of marked similarities to high- cuprate superconductors point to the realization of superconductivity in the doped Mott insulator…