Dissipative preparation of many-body Floquet Chern insulators

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.