Characterizing bulk-boundary correspondence of one-dimensional non-Hermitian interacting systems by edge entanglement entropy

Dramatically different from the Hermitian systems, the conventional bulk-boundary correspondence (BBC) is broken in the non-Hermitian systems. In this paper, we use edge entanglement entropy to characterize the topological properties of non-Hermitian Su-Schrieffer-Heeger Hubbard model. For free fermions, we study the scaling behavior of entanglement entropy and demonstrate that the edge entanglement entropy is a good indicator to delimit different phases of non-Hermitian systems. We further generalize the edge entanglement entropy to the non-Hermitian interacting Hubbard chain and obtain the topological phase diagram in the plane of interaction and non-Hermitian hopping amplitudes. It is found that the Hubbard interaction diminishes and weakens the breakdown of the bulk-boundary correspondence, which eventually disappears at some critical value of interaction.

Automated summary

This paper investigates the relationship between edge entanglement entropy and topological properties in non-Hermitian systems, and extends it to non-Hermitian interacting systems. It is found that the presence of interactions weakens the breakdown of the bulk-boundary correspondence.