Enhancing energy transfer in quantum systems via periodic driving: Floquet master equations

TL;DR

This paper investigates how periodic driving influences energy transfer efficiency in multi-level quantum systems coupled to thermal baths, comparing different master equation approaches and highlighting the role of Lamb-shift corrections.

Contribution

It develops a Floquet-type master equation for quantum systems under periodic driving, analyzing the impact on energy transfer efficiency with detailed bath and coherence effects.

Findings

Periodic driving can enhance energy transfer efficiency.

Lamb-shift corrections significantly affect energy transfer in Redfield scenarios.

Floquet-Redfield approach reveals nonnegligible effects of external driving.

Abstract

We provide a comprehensive study of the energy transfer phenomenon -- populating a given energy level -- in 3- and 4-level quantum systems coupled to two thermal baths. In particular, we examine the effects of an external periodic driving and the coherence induced by the baths on the efficiency of the energy transfer. We consider the Floquet-Lindblad and the Floquet-Redfield scenarios, which both are in the Born-Markov, weak-coupling regime but differ in the treatment of the secular approximation, and for the latter, we develop an appropriate Floquet-type master equation by employing a partial secular approximation. Throughout the whole analysis we keep Lamb-shift corrections in the master equations. We observe that, especially in the Floquet-Redfield scenario, the driving field can enhance the energy transfer efficiency compared to the nondriven scenario. In addition, unlike degenerate systems where Lamb-shift corrections do not contribute significantly on the energy transfer, in the Redfield and the Floquet-Redfield scenarios these corrections have nonnegligible effects.