Topological hierarchy insulators and topological fractal insulators
1 Department of Physics, Beijing Normal University - Beijing 100875, China
2 Department of Physics, Hebei Normal University - Hebei, 050024, China
Received: 26 July 2015
Accepted: 28 September 2015
Topological insulators are new states of quantum matter with metallic edge/surface states. In this paper, we point out that there exists a new type of particle-hole symmetry-protected topological insulator —the topological hierarchy insulator (THI), a composite topological state of a (parent) topological insulator and its defect-induced topological mid-gap states. A particular type of THI is the topological fractal insulator, which is a THI with self-similar topological structure. In the end, we also discuss the possible experimental realizations of THIs.
PACS: 73.21.Cd – Superlattices / 73.43.Cd – Theory and modeling / 71.10.Fd – Lattice fermion models (Hubbard model, etc.)
© EPLA, 2015