Quantum dynamics of a driven three-level Josephson-atom maser

TL;DR

This paper models the quantum dynamics of a driven three-level Josephson-atom maser, aligning theoretical predictions with experimental results and analyzing effects like fluctuators and semiclassical approximations.

Contribution

It provides a detailed quantum analysis of a three-level Josephson-atom maser driven by cavity modulation, matching experimental observations and exploring the impact of circuit fluctuations.

Findings

Quantum model agrees with experimental data

Fluctuators influence the maser's dynamics

Semiclassical approximation differs from quantum results

Abstract

Recently, a lasing effect has been observed in a superconducting nano-circuit where a Cooper pair box, acting as an artificial three-level atom, was coupled to a resonator. Motivated by this experiment, we analyze the quantum dynamics of a three-level atom coupled to a quantum-mechanical resonator in the presence of a driving on the cavity within the framework of the Lindblad master equation. As a result, we have access to the dynamics of the atomic level populations and the photon number in the cavity as well as to the output spectrum. The results of our quantum approach agree with the experimental findings. The presence of a fluctuator in the circuit is also analyzed. Finally, we compare our results with those obtained within a semiclassical approximation.