Bulk-Boundary Correspondence in Non-Hermitian Systems

L. Jin, Z. Song

Published 2018-09-10Version 1

Bulk-boundary correspondence is fundamental and important in topological physics; however, it is invalid in certain non-Hermitian systems. Here we report that the way of non-Hermiticity appearance may alter the system topology. The bulk-boundary correspondence is invalid if the introduced non-Hermiticity breaks the chiral-inversion symmetry of the Hermitian systems. After fixing the chiral-inversion symmetry by alternatively introducing the non-Hermiticity, the bulk-boundary correspondence recovers with all the bulk states being extended (the non-Hermitian skin effect vanishes). The vorticity of the topological defects in the vector field associated with the system Bloch Hamiltonian is a topological invariant, the change of which predicts the topological phase transition and the (non)existence of edge states. Our findings provide insightful understanding for the topological features and the bulk-boundary correspondence in non-Hermitian systems.