496 citations · 2k across the 70 of their papers we have counts for
19 papers · 1 filter
Periodic Landau gauge and Quantum Hall effect in twisted bilayer graphene
Yasumasa Hasegawa, Mahito Kohmoto
Energy versus magnetic field (Hofstadter butterfly diagram) in twisted bilayer graphene is studied theoretically. If we take the usual Landau gauge, we cannot take a finite periodi…
Edge states and topological phases in non-Hermitian systems
Kenta Esaki, Masatoshi Sato, Kazuki Hasebe +1
Topological stability of the edge states is investigated for non-Hermitian systems. We examine two classes of non-Hermitian Hamiltonians supporting real bulk eigenenergies in weak…
Electric-field induced penetration of edge states at the interface between monolayer and bilayer graphene
Yasumasa Hasegawa, Mahito Kohmoto
The edge states in the hybrid system of single-layer and double-layer graphene are studied in the tight-binding model theoretically. The edge states in one side of the interface be…
Zero modes, energy gap, and edge states of anisotropic honeycomb lattice in a magnetic field
Kenta Esaki, Masatoshi Sato, Mahito Kohmoto +1
We present systematic study of zero modes and gaps by introducing effects of anisotropy of hopping integrals for a tight-binding model on the honeycomb lattice in a magnetic field.…
Wave propagation through Cantor-set media: Chaos, scaling, and fractal structures
Kenta Esaki, Masatoshi Sato, Mahito Kohmoto
Propagation of waves through Cantor-set media is investigated by renormalization-group analysis. For specific values of wave numbers, transmission coefficients are shown to be gove…
The Hall conductance, topological quantum phase transition and the Diophantine equation on honeycomb lattice
Masatoshi Sato, Daijiro Tobe, Mahito Kohmoto
We consider a tight-binding model with the nearest neighbour hopping integrals on the honeycomb lattice in a magnetic field. Assuming one of the three hopping integrals, which we d…
Gauge fields, quantized fluxes and monopole confinement of the honeycomb lattice
Mahito Kohmoto
Electron hopping models on the honeycomb lattice are studied. The lattice consists of two triangular sublattices, and it is non-Bravais. The dual space has non-trivial topology. Th…
Wave Propagation in the Cantor-Set Media: Chaos from Fractal
Kenta Esaki, Masatoshi Sato, Mahito Kohmoto
Propagation of waves in the Cantor-set media is investigated by a renormalization-group type method. We find fixed points for complete reflection, , and for complete transmi…
Zero modes and the edge states of the honeycomb lattice
Mahito Kohmoto, Yasumasa Hasegawa
The honeycomb lattice in the cylinder geometry with zigzag edges, bearded edges, zigzag and bearded edges (zigzag-bearded), and armchair edges are studied. The tight-binding model…
Distribution of spectral-flow gaps in the Rashba model with disorder: a new universality
Daijiro Tobe, Mahito Kohmoto, Masatoshi Sato +1
We report a study of disordered electron systems with spin-orbit coupling on a cylinder using methods of random matrix ensembles. With a threading flux turned on, the single partic…
Adiabatic Process and Chern Numbers
Jun Goryo, Mahito Kohmoto
We study quantum processes with two or more adiabatic parameters. When the parameters are compactified, a derivative of the Hamiltonian gives a first Chern number, hence an integer…
Zero modes of tight binding electrons on the honeycomb lattice
Yasumasa Hasegawa, Rikio Konno, Hiroki Nakano +1
Tight binding electrons on the honeycomb lattice are studied where nearest neighbor hoppings in the three directions are and , respectively. For the isotropic case,…
Hofstadter Problem on the Honeycomb and Triangular Lattices: Bethe Ansatz Solution
M. Kohmoto, A. Sedrakyan
We consider Bloch electrons on the honeycomb lattice under a uniform magnetic field with flux per cell. It is shown that the problem factorizes to two triangular lattices.…
Propagation of Light in Cantor Media
Masanori Yamanaka, Mahito Kohmoto
We numerically find that transmission coefficients have a rich structure as a function of wavelength in Cantor media. Complete transmission and complete reflection are observed. We…
Polarization of Bloch electrons and Berry phase in the presence of electromagnetic fields
J. Goryo, M. Kohmoto
We consider Bloch electrons in the presence of the uniform electromagnetic field in two- and three-dimensions. It is renowned that the quantized Hall effect occurs in such systems.…
Berry phase and quantized Hall effect in three-dimension
J. Goryo, M. Kohmoto
We consider Bloch electrons in the electromagnetic field and argue the relation between the Berry phase and the quantized Hall conductivity in three-dimension. The Berry phase we c…
Charge and current oscillations in Fractional quantum Hall systems with edges
J. Shiraishi, Y. Avishai, M. Kohmoto
Stationary solutions of the Chern-Simons effective field theory for the fractional quantum Hall systems with edges are presented for Hall bar, disk and annulus. In the infinitely l…
Exclusonic Quasiparticles and Thermodynamics of Fractional Quantum Hall Liquids
Y. S. Wu, Y. Yu, Y. Hatsugai +1
Quasielectrons and quasiholes in the fractional quantum Hall liquids obey fractional (including nontrivial mutual) exclusion statistics. Their statistics matrix can be determined f…
Thermal activation of exclusonic quasiparticles in the fractional quantum Hall effect
J. Shiraishi, M. Kohmoto, Y. S. Wu
Quasiparticles of the fractional quantum Hall systems obey fractional (including mutual) exclusion statistics. In this note we study the effects of exclusion statistics on thermal…