52 citations · 147 across the 10 of their papers we have counts for
10 papers
Gradient flow towards quantum states with ideal quantum geometry
T. Shiga, T. Fukui
We propose a gradient-flow method for quantum states in lattice models, generated by an action consisting of the quantum-metric and the square of the Berry curvature. These two ter…
Flow of unitary matrices: Real-space winding numbers in one and three dimensions
F. Hamano, T. Fukui
The notion of the flow introduced by Kitaev is a manifestly topological formulation of the winding number on a real lattice. First, we show in this paper that the flow is quite use…
Higher-order topological heat conduction on a lattice for detection of corner states
T. Fukui, T. Yoshida, Y. Hatsugai
A heat conduction equation on a lattice composed of nodes and bonds is formulated assuming the Fourier law and the energy conservation law. Based on this equation, we propose a hig…
Streda formula for the Hofstadter-Wilson-Dirac model in two and four dimensions
T. Fukui, T. Fujiwara
We rederive the spectral asymmetry of the Wilson-Dirac model in external fields, paying attention to the Chern number due to the Berry connection. We interpret the smooth part of t…
Bulk-edge correspondence in topological pumping
Y. Hatsugai, T. Fukui
The topological pumping [1-3] is revisited from a view point of the bulk-edge correspondence. Shift of the center of mass (CM) as a pumped charge is explicitly given by the Berry c…
Disentangled topological numbers by a purification of entangled mixed states for non-interacting fermion systems
T. Fukui, Y. Hatsugai
We argue that the entanglement Chern number proposed recently is invariant under the adiabatic deformation of a gapped many-body groundstate into a {\it disentangled/purified} one,…
Majorana fermions and Z vortices on a square lattice
K. Ejima, T. Fukui
We present a simple model of Majorana fermions on a square lattice, and study zero-energy states due to Z vortices. We show the relationship between the Chern number of the gro…
Majorana zero modes bound to a vortex line in a topological superconductor
T. Fukui
We explore Majorana zero modes bound to a vortex line in a three dimensional topological superconductor model, focusing our attention on the validity of the index theorem previousl…
Topological stability of Majorana zero-modes in superconductor-topological insulator systems
T. Fukui, T. Fujiwara
We derive an index theorem for zero-energy Majorana fermion modes in a superconductor-topological insulator system in both two and three dimensions, which is valid for models with…
Quantization of non-Abelian Berry phase for time reversal invariant systems
T. Fukui, T. Fujiwara
We present a quantized non-Abelian Berry phase for time reversal invariant systems such as quantum spin Hall effect. Ordinary Berry phase is defined by an integral of Berry's gauge…