Dynamical beats of short pulses in waveguide QED

Abstract

We study weak pulse propagation through near-resonant collective media. The timescales of the pulse and the lifetime of the media are comparable. The transmitted pulse develops temporal oscillations, known as dynamical beats. We use a collection of ^{133}Cs atoms randomly captured by a nanofiber-based optical lattice. An effective macroscopic model derived from a microscopic many-atom input-output theory reproduces the observations. The results deepen our understanding of single-photon pulse propagation, crucial for many waveguide QED-based quantum information protocols.