Generic degeneracy of a non-hermitian hamiltonian implies a set of the eigenvectors is not enough to span the total linear space. One needs to extend the idea of the eigenstates to the generic ones, w...

Topological (adiabatic) pumps are typical problems where the bulk-edge correspondence is justified. The Chern number of the bulk and the behavior of the edge states are linked intimately. As for most ...

Eigenvalues may not be always real for generalized eigenvalue problems even if the Hamiltonian and overlap matrices are both Hermitian. When the overlap is associated with a norm of physical state, th...

Bulk-edge correspondence is universal. We do find a novel playground of the chiral edge states protected by bulk topology. It is in the evolutionary game theory realized in a kagome network. The paper...

We are proposing one more lattice structure with frustration that hosts flat bands, square-Kagome lattice. Using a molecular orbital representation, its flat band and flat dispersion only in some spec...

Our paper on non-real things has been picked up by JPS Hot Topics. It's real.

Motivated by the relation between the Dirac/Schrodinger hamiltonians, the square root topological phase (SRTI) has been discussed in several cases recently. Here the roles of symmetries in SRTI are fo...

Dirac cones are generically tilted when realized in a realistic material. This gapless structure is effectively protected by the generalized chiral symmetry. It induces topological edge states when th...

Zero modes of chiral symmetric systems are stable as for symmetry preserving disorder. On a honeycomb lattice with Kekule ordering, we have demonstrated this stabilities numerically. It has been pubis...

Robustness of the mirror skin effects against for randomness breaking the symmetry is demonstrated by machine learning. The letter has been published in J. Phys. Soc. Jpn. 90, 053703 (2021) by Hiromu ...