Strong-coupling limit of the driven dissipative light-matter interaction

Abstract

We approach the strong-coupling thermodynamic limit in the response of the open driven Jaynes-Cummings (JC) oscillator. We do so by highlighting the rôle of quantum fluctuations against the semiclassical response in three distinct regimes of operation. We begin by demonstrating the persistence of photon blockade, predicted in [H. J. Carmichael, Phys. Rev. X 5, 031028 (2015)], as a manifestation of the inherently-quantum and nonlinear JC spectrum revealed for vanishing dissipation. We then proceed to discuss the importance of bistability, which, despite being present in photon blockade, is able to provide an alignment between the semiclassical nonlinearity and quantum dynamics only for a driving amplitude having the same order of magnitude as the lightmatter coupling strength. This resolution brings us to the critical point of the well-known quantum phase transition of second order on resonance, where the quantum and semiclassical pictures are once more contrasted for a varying participation of the two coherent interactions when going through the collapse of the quasi-energy spectrum.

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

“…From the above background, it becomes clear that some key pieces are missing to complete the puzzle of what lies behind a mutliphoton resonance established in a quantum nonlinear oscillator with light-matter coupling. Prompted by the explanation in the above paragraph provided by Schuster and collaborators in [21] as well as by the recent demonstration of bimodality in the JC two-photon resonance [30] and some of the multimodal profiles presented in [31] when asymptotically assessing the strong-coupling limit of light-matter interaction, we may ask again what is the place of multistability in what appears to be the saturation of an effective two-level transition? How are we to understand the nonclassical nature of such an output photon stream from the visualization of fluctuations within the quantum-classical correspondence in the language of quasiprobability distributions [4,32]?…”

Time-resolved observation of a dynamical phase transition with atoms in a cavity

“…It has been shown that the blockade breaks down at very high intensities in the form of a phase transition [25][26][27][28]. The required regime of strong coupling constants is available only with circuit QED systems [29,30] using superconducting artificial atoms coupled to microwave resonators [31]. In optical resonators, and with a single atom, the photon blockade breakdown can only be realized far from the phase transition regime.…”