Band structure of the one-dimensional spin–orbit-coupled Su–Schrieffer–Heeger lattice with [formula omitted]-symmetric onsite imaginary potentials

Abstract

Energy band structures of one-dimensional non-Hermitian spin–orbit-coupled Su–Schrieffer–Heeger (SSH) model are theoretically investigated, by introducing imaginary potentials with gain and loss effects. It is found that the imaginary potentials can promote the occurrence of PT-symmetry breaking. In the topologically-nontrivial regions, the different imaginary parts of the edge-state energies leads to the different localization degrees of such states. Moreover, gapless phase regions arise between the topologically-nontrivial and -trivial regions, in which edge states are allowed to survive. Therefore, these results are helpful to understand the band-structural and topological properties of PT-symmetric non-Hermitian systems.