Quantum memory effects in atomic ensembles coupled to photonic cavities

TL;DR

This paper investigates the complex dynamics of atomic ensembles in photonic cavities, revealing effects like superradiance, energy transfer enhancement, and the influence of environmental tuning, with implications for quantum memory and information transfer.

Contribution

It provides a detailed analysis of many-body atomic systems coupled to photonic cavities, including the effects of reservoir detuning and the validity of the rotating wave approximation in different coupling regimes.

Findings

Enhanced energy transfer in atomic chains.

Modulation of atomic oscillations via environmental tuning.

Limitations of the rotating wave approximation at intermediate couplings.

Abstract

In this article we explore the dynamics of many-body atomic systems symmetrically coupled to a single Lorentzian photonic cavity. Our study reveals interesting dynamical characteristics including non-zero steady states, superradiant decay, enhanced energy transfer and the ability to modulate oscillations in the atomic system by tuning environmental degrees of freedom. We also analyse a configuration consisting of a three-atom chain embedded in a photonic cavity. Similarly, we find a strong enhancement of the energy transfer rate between the two ends of the chain and identified specific initial conditions that lead to significantly reduced dissipation between the two atoms at the end of the chain. Another configuration of interest consists of two symmetrical detuned reservoirs with respect to the atomic system. In the single-atom case, we show that it is possible to enhance the decay rate of the system by modulating its reservoir detuning, while in the many-atom case, this results in dynamics akin to the on-resonant cavity. Finally, we examine the validity of rotating wave approximation through a direct comparison against the numerically exact hierarchical equations of motion approach. We find good agreement in the weak coupling regime while in the intermediate coupling regime, we identify qualitative similarities, but the rotating wave approximation becomes less reliable. In the moderate coupling regime, we find deviation of the steady states due to the formation of mixed photon atom states.