2 papers
physics.optics2024
Band structures of generalized eigenvalue equation and conic section
Takuma Isobe, Tsuneya Yoshida, Yasuhiro Hatsugai
Band structures of several metamaterials are described by generalized eigenvalue equations where complex bands emerge even if the involved matrices are Hermitian. In this paper, we…
physics.optics2021
Topological band theory of a generalized eigenvalue problem with Hermitian matrices: Symmetry-protected exceptional rings with emergent symmetry
Takuma Isobe, Tsuneya Yoshida, Yasuhiro Hatsugai
So far, topological band theory is discussed mainly for systems described by eigenvalue problems. Here, we develop a topological band theory described by a generalized eigenvalue p…