Dissipative preparation of many-body Floquet Chern insulators

TL;DR

This paper demonstrates how a periodically driven dissipative Haldane model can be tuned to achieve a topologically non-trivial steady state, effectively creating a many-body Floquet Chern insulator even in the presence of dissipation.

Contribution

It introduces a method to realize and characterize many-body Floquet Chern insulators in dissipative environments, including a generalized topological invariant for out-of-equilibrium states.

Findings

Topological steady states can be achieved at finite temperatures.

Chern insulators can be prepared in pure steady states with dissipation.

A generalized Chern invariant reflects the topology of out-of-equilibrium states.

Abstract

Considering coupling to a micro-structured bath as a relaxation mechanism in a periodically driven dissipative Haldane model, we establish that the system may be tuned to a stroboscopic topological steady state at all finite temperatures. The amplitude and frequency of the periodic drive is so chosen that the Floquet Hamiltonian describing the Haldane model at stroboscopic instants of time in the unitary situation is topologically non-trivial. We establish that in the stroboscopic steady state, the system reaches a thermal state of the Floquet Hamiltonian at a controlled temperature. Further, it is observed that even with a coupling to a quasi-local bath, remarkably a Chern insulator can indeed be prepared in a Chern non-trivial pure steady state which is expected to exhibit a stroboscopic bulk-boundary correspondence. Using the non-uniqueness of the macroscopic bulk electric polarisation of a Chern insulator in its topological phase, we propose a generalised Chern invariant that reflects the topology of out-of-equilibrium many-body stroboscopic states of the Haldane model even in a dissipative ambience. The generalised topology of dynamical Chern insulators being dependent on single-particle correlations, is expected to manifest in experiments probing many-body quantum observables.