Efficiency of feedback process in cavity quantum electrodynamics

TL;DR

This paper analyzes a feedback scheme in cavity quantum electrodynamics, revealing how the spectral function of emitted photons changes over multiple rounds, leading to decreased efficiency in generating entangled atomic states.

Contribution

It provides an analytical study of the spectral function evolution in a feedback process for entanglement generation in cavity QED.

Findings

Spectral function of emitted photons is analytically derived.

Repeated feedback rounds cause spectral function deviation.

Efficiency of entanglement generation deteriorates over multiple rounds.

Abstract

Utilizing the continuous frequency mode quantization scheme, we study from first principle the efficiency of a feedback scheme that can generate maximally entangled states of two atoms in an optical cavity through their interactions with a single input photon. The spectral function of the photon emitted from the cavity, which will be used as the input of the next round in the feedback process, is obtained analytically. We find that the spectral function of the photon is modified in each round and deviates from the original one. The efficiency of the feedback scheme consequently deteriorates gradually after several rounds of operation.