Many-body localization in a non-Hermitian quasi-periodic system

TL;DR

This study investigates the complex interplay of interaction, topology, quasiperiodicity, and non-Hermiticity in a 1D bosonic lattice model, revealing phase transitions and their effects on system dynamics.

Contribution

It introduces a model exhibiting simultaneous real-complex, topological, and MBL phase transitions, highlighting differences from single-particle systems and proposing their convergence in the thermodynamic limit.

Findings

Imaginary parts of eigenenergies are suppressed by MBL.

Topological phase transition is identified via winding number.

Phase transitions significantly influence system dynamics.

Abstract

In the present study, the interplay among interaction, topology, quasiperiodicity, and non-Hermiticity is studied. The hard-core bosons model on a one-dimensional lattice with asymmetry hoppings and quasiperiodic onsite potentials is selected. This model, which preserves time-reversal symmetry (TRS), will exhibit three types of phase transition: real-complex transition of eigenenergies, topological phase transition and many-body localization (MBL) phase transition. For thereal-complex transition, it is found that the imaginary parts of the eigenenergies are always suppressed by the MBL. Moreover, by calculating the winding number, a topological phase transition can be revealed with the increase of potential amplitude, and we find that the behavior is quite different from the single-particle systems. Based on our numerical results, we conjecture that these three types of phase transition occur at the same point in the thermodynamic limit, and the MBL transition of quasiperiodic system and disordered system should belong to different universality classes. Finally, we demonstrate that these phase transitions can profoundly affect the dynamics of the non-Hermitian many-body system.