Visualizing the breakdown of quantum multimodality in coherently driven light-matter interaction

TL;DR

This paper investigates how quantum multimodality diminishes in the strong-coupling limit of the Jaynes-Cummings model under weak driving, highlighting quantum fluctuations and revealing quantum beats in photon correlations.

Contribution

It introduces a perturbative approach to analyze quantum fluctuations and demonstrates the collapse of multimodality and the emergence of quantum beats in the JC model.

Findings

Quantum multimodality collapses in the strong-coupling limit.

Quantum beats are observed in the intensity correlation function.

Interference effects relate to the JC spectrum and phase-space Wigner function.

Abstract

We show that the saturation of a multiphoton transition is accompanied by a gradual collapse of quantum multimodality in the strong-coupling limit of the weakly driven Jaynes-Cummings (JC) model. By means of a perturbative method, we illustrate the prominent role of quantum fluctuations by focusing on the two and three-photon resonance operation in a regime where the steady-state average photon number is below or marginally above unity. We also reveal two coexistent quantum beats in the intensity correlation function of the forwards scattered photons. These beats, originating from the states mediating the cascaded decay, arise as a direct consequence of the distinct JC spectrum. Their interference coordinates with the alternation of positive and negative values of the Wigner function around the phase-space origin in the transient conditioned on a photodetection.