Single collective excitation of an atomic array trapped along a waveguide: a study of cooperative emission for different atomic chain configurations

TL;DR

This paper investigates how the arrangement of atoms near a waveguide influences the emission of a single collective excitation, revealing possibilities for directing, enhancing, or localizing light through geometric configurations.

Contribution

It introduces a detailed analysis of cooperative emission in atomic arrays with various configurations, highlighting control over light emission via geometry.

Findings

Atomic arrays can redirect emitted light.

Geometry influences emission directionality and intensity.

Atomic mirrors can localize light in a cavity.

Abstract

Ordered atomic arrays trapped in the vicinity of nanoscale waveguides offer original light-matter interfaces, with applications to quantum information and quantum non-linear optics. Here, we study the decay dynamics of a single collective atomic excitation coupled to a waveguide in different configurations. The atoms are arranged as a linear array and only a segment of them is excited to a superradiant mode and emits light into the waveguide. Additional atomic chains placed on one or both sides play a passive role, either reflecting or absorbing this emission. We show that when varying the geometry, such a one-dimensional atomic system could be able to redirect the emitted light, to directionally reduce or enhance it, and in some cases to localize it in a cavity formed by the atomic mirrors bounding the system.