Superradiance for atoms trapped along a photonic crystal waveguide

TL;DR

This paper demonstrates superradiance in atoms trapped near a photonic crystal waveguide, showing enhanced emission rates and paving the way for studying photon-mediated interactions in many-body quantum systems.

Contribution

The study reports the first observation of superradiance in atoms coupled to a photonic crystal waveguide with quantifiable emission rate scaling.

Findings

Superradiant emission rate scales with atom number as $ar{ abla}_{ m SR}ar{N} imesar{ abla}_{ m 1D}$

Achieved strong atom-photon interaction near the band edge of the PCW

Measured single-atom decay rate into guided mode as $ ext{1.1} imes$ free space rate

Abstract

We report observations of superradiance for atoms trapped in the near field of a photonic crystal waveguide (PCW). By fabricating the PCW with a band edge near the D$_1$ transition of atomic cesium, strong interaction is achieved between trapped atoms and guided-mode photons. Following short-pulse excitation, we record the decay of guided-mode emission and find a superradiant emission rate scaling as $\bar{\Gamma}_{\rm SR}\propto\bar{N}\cdot\Gamma_{\rm 1D}$ for average atom number $0.19 \lesssim \bar{N} \lesssim 2.6$ atoms, where $\Gamma_{\rm 1D}/\Gamma_0 =1.1\pm0.1$ is the peak single-atom radiative decay rate into the PCW guided mode and $\Gamma_{0}$ is the Einstein-$A$ coefficient for free space. These advances provide new tools for investigations of photon-mediated atom-atom interactions in the many-body regime.