Correlation-induced phase transitions and mobility edges in an interacting non-Hermitian quasicrystal

TL;DR

This paper investigates how quantum interactions influence phase transitions, localization, and entanglement in non-Hermitian quasicrystals, revealing that interactions can control critical points and induce mobility edges.

Contribution

It demonstrates that onsite interactions in a non-Hermitian quasicrystal shift phase transition thresholds and enable the emergence of mobility edges, expanding understanding of disorder-interaction interplay.

Findings

Interactions lower PT and localization transition thresholds.

Interaction-induced critical phase with mobility edges.

Control of phase domains via tuning interaction strength.

Abstract

Non-Hermitian quasicrystal constitutes a unique class of disordered open system with PT-symmetry breaking, localization and topological triple phase transitions. In this work, we uncover the effect of quantum correlation on phase transitions and entanglement dynamics in non-Hermitian quasicrystals. Focusing on two interacting bosons in a Bose-Hubbard lattice with quasiperiodically modulated gain and loss, we find that the onsite interaction between bosons could drag the PT and localization transition thresholds towards weaker disorder regions compared with the noninteracting case. Moreover, the interaction facilitates the expansion of the critical point of a triple phase transition in the noninteracting system into a critical phase with mobility edges, whose domain could be flexibly controlled by tuning the interaction strength. Systematic analyses of the spectrum, inverse participation ratio, topological winding number, wavepacket dynamics and entanglement entropy lead to consistent predictions about the correlation-driven phases and transitions in our system. Our findings pave the way for further studies of the interplay between disorder and interaction in non-Hermitian quantum matter.