Effects of retardation on many-body superradiance in chiral waveguide QED

TL;DR

This paper investigates how retardation effects influence many-body superradiance in a chiral waveguide, revealing a maximum effective atom number, formation of superradiant domains, and oscillatory emission dynamics.

Contribution

It introduces an exact master equation approach that includes delay effects, uncovering new phenomena like emission rate plateaus and persistent oscillations in superradiant systems.

Findings

Identification of a maximum number of atoms contributing to superradiance

Discovery of superradiant domain formation from inter-atomic correlations

Observation of persistent oscillatory atomic dynamics with emission bursts

Abstract

We study the superradiant decay of a chain of atoms coupled to a chiral waveguide, focusing on the regime of non-negligible photon propagation time. Using an exact master equation description which accounts for delay effects, we obtain evidence to suggest that competition between collective decay and retardation leads to the emergence of an effective maximum number of atoms able to contribute to the superradiant dynamics, resulting in a plateau of the peak emission rate. To develop this analysis further, we investigate the inter-atomic correlations to find features consistent with the formation of individual superradiant domains. Moreover, we find that retardation can also result in persistent oscillatory atomic dynamics accompanied by a periodic sequence of emission bursts.