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arXiv · 1909.01346

Entanglement spectrum and entropy in topological non-Hermitian systems and non-unitary conformal field theories

Po-Yao Chang·Jhih-Shih You·Xueda Wen·Shinsei Ryu
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Abstract

We propose a method of computing and studying entanglement quantities in non-Hermitian systems by use of a biorthogonal basis. We find that the entanglement spectrum characterizes the topological properties in terms of the existence of mid-gap states in the non-Hermitian Su-Schrieffer-Heeger (SSH) model with parity and time-reversal symmetry (PT symmetry) and the non-Hermitian Chern insulators. In addition, we find that at a critical point in the PT symmetric SSH model, the entanglement entropy has a logarithmic scaling with corresponding central charge $c=-2$. This critical point then is a free-fermion lattice realization of the non-unitary conformal field theory.

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Po-Yao Chang, Jhih-Shih You, Xueda Wen, Shinsei Ryu. 2019-09-03. Entanglement spectrum and entropy in topological non-Hermitian systems and non-unitary conformal field theories. https://doi.org/10.1103/physrevresearch.2.033069

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