Deep Strong Coupling Regime of the Jaynes-Cummings model

TL;DR

This paper explores the quantum dynamics in the deep strong coupling regime of the Jaynes-Cummings model, revealing photon wavepacket bouncing, collapse, and revivals beyond the rotating-wave approximation.

Contribution

It introduces an intuitive physical framework to describe the deep strong coupling regime where traditional approximations fail.

Findings

Photon wavepackets bounce along parity chains

Collapse and revivals of qubit population observed

Analytical and numerical analysis of photon statistics and phase space

Abstract

We study the quantum dynamics of a two-level system interacting with a quantized harmonic oscillator in the deep strong coupling regime (DSC) of the Jaynes-Cummings model, that is, when the coupling strength g is comparable or larger than the oscillator frequency w (g/w > 1). In this case, the rotating-wave approximation cannot be applied or treated perturbatively in general. We propose an intuitive and predictive physical frame to describe the DSC regime where photon number wavepackets bounce back and forth along parity chains of the Hilbert space, while producing collapse and revivals of the initial population. We exemplify our physical frame with numerical and analytical considerations in the qubit population, photon statistics, and Wigner phase space.