Atom-field correlations in the weak-excitation limit of absorptive optical bistability

TL;DR

This paper investigates atom-field correlations in absorptive optical bistability under weak excitation, using a linearized quantum fluctuation approach and phase-space analysis, highlighting nonclassical features in collective strong coupling regimes.

Contribution

It introduces a linearized Fokker-Planck framework in the positive P representation for analyzing atom-field correlations without adiabatic elimination.

Findings

Correlation functions calculated in the weak-excitation limit.

Comparison with experimental cavity transmission spectra.

Identification of nonclassical anomalous correlations.

Abstract

We calculate the steady-state and first-order time varying atom-field correlation functions in the weak-excitation limit of absorptive optical bistability from a linearized theory of quantum fluctuations. We formulate a Fokker-Planck equation in the positive P representation following the phase-space analysis of [H. J. Carmichael, Phys. Rev. A 33, 3262 (1986)] which is suitable for the determination of cross-correlations as it does not resort to adiabatic elimination. Special emphasis is placed on the limit of collective strong coupling as attained from a vanishing photon-loss rate. We compare to the cavity-transmission spectrum with reference to experimental results obtained for macroscopic dissipative systems, discussing the role of anomalous correlations arising as distinct nonclassical features.