Dynamics Near a Photonic Band-Edge: Strong Coupling Effects Beyond Rotating-Wave Approximation

TL;DR

This paper investigates how strong coupling and non-Markovian effects influence quantum emitter dynamics near a photonic band-edge, revealing significant modifications beyond the rotating-wave approximation.

Contribution

It introduces a nonperturbative approach to analyze strong system-bath coupling effects beyond the rotating-wave approximation in photonic crystal environments.

Findings

Freezing of spontaneous emission is altered by counter-rotating terms.

Maximum light-matter entanglement is significantly affected.

Atom-photon bound states have increased lifetimes beyond RWA assumptions.

Abstract

We study the dynamics of a quantum emitter coupled to a two-dimensional photonic crystal featuring a finite bandwidth with sharp edges and a Van-Hove singularity. We study the effect of strong system-bath coupling and non-Markovianity of the photonic environment using a nonperturbative approach based on the recently introduced NCA dynamical map for open quantum systems. We show that several characteristic features of the dynamics near a photonic band-edge such as the freezing of spontaneous emission and the maximum light-matter entanglement, get strongly modified in presence of counter-rotating terms in the system-bath coupling, beyond the rotating-wave approximation. Furthermore, by computing the spectral function of the quantum emitter we comment on the role played by atom-photon bound-state and show that this acquires a much larger lifetime once the rotating-wave approximation is relaxed.