The entanglement spectrum (ES) encodes the topological properties of a system due to the bulk-boundary correspondence. However, in non-Hermitian systems, the bulk-boundary correspondence is in general broken. This raises the question of whether you can still learn anything about the topology of a non-Hermitian system through the entanglement spectrum. In this talk, I will review the definition and importance of the ES for Hermitian systems, explain how it is generalized to the non-Hermitian case, and use the example of the non-Hermitian SSH chain to explore what topological properties are inherited by the ES in different phases. Mostly based on the paper: Ortega-Taberner, C., Rødland, L., & Hermanns, M. (2022). Polarization and entanglement spectrum in non-Hermitian systems.
PRB, 105(7). arXiv:2111.07788