Non-Hermiticity induced topological edge states with unique transport

Abstract

Abstract We demonstrate that non-Hermiticity solely induced Su-Schrieffer-Heeger (SSH) lattice can result in two unique topological edge state (TES) bands: One is within the band gap, the other is embedded in the bulky bands. The latter are the topological bound states in the continuum (BIC). Different from general TESs, both the TES bands have the unidirectional transport with the direction under two-fold modulation: source spin direction and source position. The TESs with BIC have additional amplifying transport property. All the results have developed the concept of BICs and TESs, and provided a new freedom in the controlling of light transport.