Entanglement phase transitions in non-Hermitian quasicrystals

TL;DR

This paper uncovers entanglement phase transitions in non-Hermitian quasicrystals, revealing novel scaling laws and critical behaviors due to the interplay of non-Hermitian effects and quasiperiodic potentials.

Contribution

It identifies and characterizes two distinct types of entanglement transitions in NHQCs, including a novel log-law to area-law transition mediated by a critical phase.

Findings

Volume-law to area-law transition coincides with PT-symmetry breaking.

Log-law to area-law transition occurs through a critical phase.

Demonstrated in two representative NHQC models.

Abstract

The scaling law of entanglement entropy could undergo qualitative changes during the nonunitary evolution of a quantum many-body system. In this work, we uncover such entanglement phase transitions in one-dimensional non-Hermitian quasicrystals (NHQCs). We identify two types of entanglement transitions with different scaling laws and critical behaviors due to the interplay between non-Hermitian effects and quasiperiodic potentials. The first type represents a typical volume-law to area-law transition, which happens together with a PT-symmetry breaking and a localization transition. The second type features an abnormal log-law to area-law transition, which is mediated by a critical phase with a volume-law scaling in the steady-state entanglement entropy. These entangling phases and transitions are demonstrated in two representative models of NHQCs. Our results thus advanced the study of entanglement transitions in non-Hermitian disordered systems and further disclosed the rich entanglement patterns in NHQCs.