Markovian Master Equation and Thermodynamics of Two-level System in Strong Laser Field

TL;DR

This paper applies a combined weak coupling and Floquet formalism to analyze the thermodynamics of a strongly driven two-level atom interacting with heat baths, deriving resonance fluorescence formulas and exploring heat pump regimes.

Contribution

It introduces a thermodynamical approach to a strongly driven two-level system, deriving new formulas for resonance fluorescence and identifying heat pump regimes.

Findings

Derived the Mollow triplet with detailed differences from standard models.

Showed the system can operate as a heat pump depending on detuning.

Identified regimes where the system heats or cools reservoirs using laser work.

Abstract

The recently developed technique combining the weak coupling limit with the Floquet formalism is applied to a model of two-level atom driven by a strong laser field and weakly coupled to heat baths. Firstly, the case of a single electromagnetic bath at zero temperature is discussed and the formula for resonance fluorescence is derived. The expression describes the well-known Mollow triplet, but its details differ from the standard ones based on additional simplifying assumptions. The second example describes the case of two thermal reservoirs: an electromagnetic one at finite temperature and the second dephasing one, which can be realized as a phononic or buffer gas reservoir. It is shown using the developed thermodynamical approach that the latter system can work in two regimes depending on the detuning sign: a heat pump transporting heat from the dephasing reservoir to an electromagnetic bath or can heat both, always at the expense of work supplied by the laser field.