Jaynes-Cummings dynamics in strong coupling for many-interacting-qubit quantum Rabi models

TL;DR

This paper investigates the complex dynamics of many-interacting-qubit systems in cavity QED, revealing that collective effects can produce Jaynes-Cummings behavior even under strong coupling conditions.

Contribution

It redefines the criteria for strong and weak coupling regimes in many-body spin-cavity systems, highlighting counter-intuitive dynamical effects across different models.

Findings

Counter-intuitive Jaynes-Cummings dynamics occur despite strong coupling.

Effective collective coupling can differ from individual couplings.

Results are demonstrated in two-qubit, two-qutrit, and N-qubit models.

Abstract

The present work focuses on the strong/weak interaction of many-body spin-systems with a cavity mode. It introduces the necessity of redefining the physical conditions determining the strong/weak coupling regime in those systems. In more complex systems, the effective coupling emerging from the collective dynamics may differ indeed from the actual coupling of each individual subsystem with the bosonic field. This is shown by highlighting some counter-intuitive dynamical effects properly related to the coupling regime: a Jaynes-Cummings dynamics emerging although a strong interaction is present. The universality of this result is demonstrated through the analysis of three distinct systems: a two-qubit, a two-qutrit, and an $N$-qubit chain quantum Rabi models.