Entanglement spectrum and entropy in topological non-Hermitian systems and nonunitary conformal field theory

This paper studies the entanglement properties of free-fermion systems without hermiticity. From the entanglement entropy scaling, the authors identify the non-unitary conformal field theory with c=-2 in a PT-symmetric non-Hermitian lattice system hosting topological phases. The entanglement spectrum also can detect the topological properties in the gapped phases, including the PT-symmetric Su-Schrieffer-Heeger model and the non-Hermitian Chern insulator.