Hidden multi-topological phases mediated by constrained inter-cell coupling
Ziteng Wang·Hrvoje Buljan·Domenico Bongiovanni·Dario Jukić·Zhichan Hu·Xiangdong·Roberto Morandotti·Daohong Song·Jingjun Xu·Zhigang Chen
Abstract The discovery of topological phases of matter and topological boundary states had a tremendous impact on condensed matter physics, photonics, and material sciences, where topological phases are defined via energy bands, described by the topological band theory. However, there are topological materials that cannot be described by this theory, which support non-trivial boundary states but are little-known and largely unexplored. Here, we uncover a new class of topological phases—termed "m