Quantum trajectories, feedback and squeezing

TL;DR

This paper explores how quantum trajectory theory can be used to improve the squeezing of fluorescence light emitted by a two-level atom through feedback control based on homodyne detection.

Contribution

It introduces a feedback scheme within quantum trajectory theory to enhance light squeezing from a two-level atom under continuous observation.

Findings

Feedback improves squeezing levels.

Squeezing depends on control parameters.

Optimal feedback settings enhance quantum light properties.

Abstract

Quantum trajectory theory is the best mathematical set up to model continual observations of a quantum system and feedback based on the observed output. Inside this framework, we study how to enhance the squeezing of the fluorescence light emitted by a two-level atom, stimulated by a coherent monochromatic laser. In the presence of a Wiseman-Milburn feedback scheme, based on the homodyne detection of a fraction of the emitted light, we analyze the squeezing dependence on the various control parameters.