229 citations · 764 across the 21 of their papers we have counts for
21 papers
Quantum spin Hall states in the lateral heteromonolayers of WTe2-MoTe2
Mari Ohfuchi, Akihiko Sekine
We used density functional theory to investigate the lateral heteromonolayers of WTe2 and MoTe2. We confirmed that topologically nontrivial and trivial phases are energetically fav…
Emergent One-Dimensional Helical Channel in Higher-Order Topological Insulators with Step Edges
Akihiko Sekine, Manabu Ohtomo, Kenichi Kawaguchi +1
We study theoretically the electronic structure of three-dimensional (3D) higher-order topological insulators in the presence of step edges. We numerically find that a 1D conductin…
Electronic properties of the steps in bilayer Td-WTe2
Mari Ohfuchi, Akihiko Sekine, Manabu Ohtomo +1
Monolayer WTe2 stripes are quantum spin Hall (QSH) insulators. Density functional theory was used for investigating the electronic properties of the stripes and steps in bilayer Td…
Axion Quasiparticles for Axion Dark Matter Detection
Jan Schütte-Engel, David J. E. Marsh, Alexander J. Millar +7
It has been suggested that certain antiferromagnetic topological insulators contain axion quasiparticles (AQs), and that such materials could be used to detect axion dark matter (D…
Axion Electrodynamics in Topological Materials
Akihiko Sekine, Kentaro Nomura
One of the intriguing properties characteristic to three-dimensional topological materials is the topological magnetoelectric phenomena arising from a topological term called the $…
Valley Pumping via Edge States and the Nonlocal Valley Hall Effect in Two-Dimensional Semiconductors
Akihiko Sekine, Allan H. MacDonald
Recent experiments have studied the temperature and gate voltage dependence of nonlocal transport in bilayer graphene, identifying features thought to be associated with the two-di…
Quantum Kinetic Theory of Thermoelectric and Thermal Transport in a Magnetic Field
Akihiko Sekine, Naoto Nagaosa
We present a general quantum kinetic theory that accounts for the interplay between a temperature gradient, momentum-space Berry curvatures of Bloch electrons, and Bloch-state scat…
Tunable Charged Domain Wall from Topological Confinement in Nodal-Line Semimetals
Akihiko Sekine, Naoto Nagaosa
We study theoretically the electronic structure of topological nodal-line semimetals. We show that, in the presence of a gap-opening spatially dependent mass term that forms a doma…
Valley-Dependent Magnetoresistance in Two-Dimensional Semiconductors
Akihiko Sekine, Allan H. MacDonald
We show theoretically that two-dimensional direct-gap semiconductors with a valley degree of freedom, including monolayer transition-metal dichalcogenides and gapped bilayer graphe…
Quantum Kinetic Theory of the Chiral Anomaly
Akihiko Sekine, Dimitrie Culcer, Allan H. MacDonald
We present a general quantum kinetic theory of low-field magnetotransport in weakly disordered crystals that accounts fully for the interplay between electric-field induced interba…
Inter-band Coherence Response to Electric Fields in Crystals
Dimitrie Culcer, Akihiko Sekine, Allan H. MacDonald
In solid state conductors, linear response to a steady electric field is normally dominated by Bloch state occupation number changes that are correlated with group velocity and lea…
Electric-Field-Induced Spin Resonance in Antiferromagnetic Insulators: Inverse Process of the Dynamical Chiral Magnetic Effect
Akihiko Sekine, Takahiro Chiba
We propose a realization of the electric-field-induced antiferromagnetic resonance. We consider three-dimensional antiferromagnetic insulators with spin-orbit coupling characterize…
Chiral Gravitomagnetic Effect in Topological Superconductors and Superfluids
Akihiko Sekine
We theoretically search for dynamical cross-correlated responses of three-dimensional topological superconductors and superfluids. It has been suggested that a gravitational topolo…
Chiral Magnetic Effect and Anomalous Hall Effect in Antiferromagnetic Insulators with Spin-Orbit Coupling
Akihiko Sekine, Kentaro Nomura
We search for dynamical magnetoelectric phenomena in three-dimensional correlated systems with spin-orbit coupling. We focus on the antiferromagnetic insulator phases where the dyn…
Stability of Multinode Dirac Semimetals against Strong Long-Range Correlations
Akihiko Sekine, Kentaro Nomura
We study the stability of Dirac semimetals with nodes in three spatial dimensions against strong Coulomb interactions. We particularly study the cases of and …
Axionic Antiferromagnetic Insulator Phase in a Correlated and Spin-Orbit Coupled System
Akihiko Sekine, Kentaro Nomura
We study theoretically a three-dimensional correlated and spin-orbit coupled system, the half-filled extended Fu-Kane-Mele-Hubbard model on a diamond lattice, focusing on the topol…
Phase structure of topological insulators by lattice strong-coupling expansion
Yasufumi Araki, Taro Kimura, Akihiko Sekine +2
The effect of the strong electron correlation on the topological phase structure of 2-dimensional (2D) and 3D topological insulators is investigated, in terms of lattice gauge theo…
Weyl Semimetal in the Strong Coulomb Interaction Limit
Akihiko Sekine, Kentaro Nomura
We study the effects of strong long-range Coulomb interactions in a Weyl semimetal. We consider a three-dimensional (3D) Dirac fermion system on a lattice with a time-reversa…
Strong Coupling Expansion in a Correlated Three-Dimensional Topological Insulator
Akihiko Sekine, Takashi Z. Nakano, Yasufumi Araki +1
Motivated by recent studies which show that topological phases may emerge in strongly correlated electron systems, we theoretically study the strong electron correlation effect in…
Electron Correlation Induced Spontaneous Symmetry Breaking and Weyl Semimetal Phase in a Strongly Spin-Orbit Coupled System
Akihiko Sekine, Kentaro Nomura
We study theoretically the electron correlation effect in a three-dimensional Dirac fermion system which describes a topologically nontrivial state. It is shown within the mean-fie…
Polar Charge Fluctuation and Superconductivity in Organic Conductor
Akihiko Sekine, Joji Nasu, Sumio Ishihara
Superconductivity and polar charge fluctuation are studied in an organic conductor with the dimer-molecule degree of freedom. The extended Hubbard models, where the intra-dimer ele…