Emergence of non-trivial phases in interacting non-Hermitian quasiperiodic chains with power-law hopping

TL;DR

This paper explores how interactions and long-range hopping in non-Hermitian quasiperiodic chains lead to the emergence of new non-trivial phases, including a topologically trivial regime with real spectra and multifractal states, challenging previous assumptions.

Contribution

It uncovers a topologically trivial intermediate phase with real spectra in interacting non-Hermitian quasiperiodic systems, influenced by long-range hopping and interactions, expanding understanding of phase emergence.

Findings

Real spectra can occur in a topologically trivial regime with multifractal states.

Interactions destroy multifractal and mobility edges present in non-interacting systems.

Long-range hopping affects the presence of boundary skin modes in the ergodic regime.

Abstract

In the last few years, several works have identified the concurrence of the spectral, delocalization-localization and topological phase transitions in non-Hermitian quasiperiodic systems in the presence of time-reversal symmetry (TRS), with or without interaction. In this work, we investigate one-dimensional interacting non-Hermitian quasiperiodic lattices with asymmetric power-law hopping and unveil that although the Hamiltonian respects the TRS, the reality of the eigenspectrum does not necessarily indicate a topologically trivial non-Hermitian many-body localization (NHMBL) regime. In fact, we reveal the emergence of a topologically trivial intermediate regime, where the states that are primarily multifractal in nature can also possess a fully real spectrum, thereby restoring the TRS before crossing over to the NHMBL phase. Moreover, in the entire intermediate regime, the interaction completely destroys the multifractal and mobility edges observed in the non-interacting counterpart. Besides, we unveil that due to the long-range nature of the hopping, the entire topologically non-trivial ergodic regime under the periodic boundary condition does not always give rise to boundary localized skin modes under the open boundary condition. Our findings thus advances and deepens the understanding about the emergence of non-trivial phases due to the interplay of interaction and long-range hopping in non-Hermitian quasiperiodic systems.