Dissipative Floquet engineering of gapped many-body phases using thermal baths

TL;DR

This paper proposes a dissipative method using thermal baths to prepare and stabilize gapped many-body phases in Floquet-engineered systems, overcoming heating and excitation challenges.

Contribution

It introduces a general dissipative strategy coupling driven systems to thermal baths to maintain effective ground states despite Floquet heating.

Findings

The approach suppresses Floquet heating effectively.

Steady states with high occupation of effective ground states are achievable.

Verified using a driven Bose-Hubbard chain example.

Abstract

Floquet engineering, the control of a quantum system by means of time-periodic driving, allows to modify the properties of the system so that it becomes described by an approximate effective time-independent Hamiltonian. However, in the presence of interactions the stabilization of interesting many-body ground states of such effective Hamiltonians is possible only on a certain time scale, beyond which Floquet heating sets in, as it results from unwanted driving induced resonant excitation. Moreover, already the preparation of such states is challenged by excitations due to imperfect adiabatic dynamics, especially when a phase transition has to be passed. Here, we propose a general dissipative strategy for the preparation and stabilization of effective ground states that are protected by an energy gap. Our approach relies on coupling the driven system to a thermal bath, the properties of which are chosen so that it both suppresses Floquet heating and guides the system into a non-equilibrium steady state with a large occupation of the effective ground-state, but generally non-thermal occupations of excited states of the effective Hamiltonian. We use the Floquet-Born-Markov master equation to verify the proposed strategy for the example of a strongly driven Bose-Hubbard chain with an effective gapped Mott-insulator ground state.