Optical bistability in strong-coupling cavity QED with a few atoms

TL;DR

This paper provides exact quantum solutions for optical bistability in a few-atom cavity QED system, demonstrating that semiclassical approximations remain accurate even with few atoms and revealing complex atom-field correlations at high drive strengths.

Contribution

It offers the first exact quantum numerical analysis of optical bistability in few-atom strong-coupling cavity QED, bridging quantum and semiclassical descriptions.

Findings

Semiclassical results are accurate for many quantities even with few atoms.

Quantum cross-correlations become significant under strong driving.

Exact solutions confirm the validity of semiclassical approximations in this regime.

Abstract

We present exact numerical solutions of the damped-driven Jaynes--Cummings model adapted to describe absorptive optical bistability in the limit of a few atoms strongly coupled to a high-finesse resonator. We show that the simplifying semiclassical result for many physical quantities of interest is well reproduced by the quantum model including even with only a few atoms in the strongly coupled system. Nontrivial atom-field quantum cross-correlations show up in the strong-driving limit.