Chiral metals and entrapped insulators in a one-dimensional topological non-Hermitian system

In this work, we study many-body steady states that arise in the non-Hermitian generalization of the noninteracting Su-Schrieffer-Heeger model at a finite density of fermions. We find that the hitherto known phase diagrams for this system, derived from the single-particle gap closings, in fact correspond to distinct nonequilibrium phases, which either carry finite currents or are dynamical insulators where particles are entrapped. Each of these have distinct quasiparticle excitations and steady-state correlations and entanglement properties. Looking at finite-sized systems, we further modulate the boundary to uncover the topological features in such steady states, particularly the emergence of leaky boundary modes. Using a variety of analytical and numerical methods, we develop a theoretical understanding of the various phases and their transitions, and we uncover the rich interplay of nonequilibrium many-body physics, quantum entanglement, and topology in a simple looking yet rich model system.

Automated summary

In this study, we investigate many-body steady states in the non-Hermitian generalization of the noninteracting Su-Schrieffer-Heeger model at a finite density of fermions. We discover distinct nonequilibrium phases, each with unique quasiparticle excitations and steady-state correlations and entanglement properties. By modulating the boundary, we uncover the topological features in these steady states.