Detection of light-matter interaction in the weak coupling regime by quantum light

TL;DR

This paper demonstrates a method using Mollow spectroscopy with quantum light to detect weak light-matter interactions in cavity QED and optomechanical systems, achieving high accuracy even at very low interaction strengths.

Contribution

The study introduces a novel application of Mollow spectroscopy with quantum light to measure weak interactions in quantum systems, including the JC model and optomechanics.

Findings

Weak interactions can be detected with high precision using quantum light.

Optimal excitation occurs between the central and side peaks of the spectrum.

Method is feasible for current experimental setups at very low interaction strengths.

Abstract

Mollow spectroscopy is a photon statistics spectroscopy, obtained by scanning the quantum light scattered from a source system. Here, we apply this technique to detect the weak light-matter interaction between the cavity and atom (or a mechanical oscillator) when the strong system dissipation is included. We find that the weak interaction can be measured with high accuracy when exciting the target cavity by quantum light scattered from the source in the halfway between the central peak and each side peak. This originally comes from the strong correlation of the injected quantum photons. In principle, our proposal can be applied into the normal cavity quantum electrodynamics (QED) system described by JC model and optomechanical system. Furthermore, it is state-of-the-art for experiment even when the interaction strength is downed to a very small value.