Multiband and array effects in matter-wave-based waveguide QED

TL;DR

This paper develops a theoretical approach to analyze matter-wave-based waveguide QED systems, revealing new bound states, emission mechanisms, and polaritons, and compares results with recent experiments.

Contribution

It introduces an infinite product method to study quantum emitters coupled to waveguides without dispersion approximation, providing detailed spectral insights.

Findings

Identification of in-gap bound states

Discovery of new emission enhancement mechanisms

Observation of matter-wave polaritons

Abstract

Recent experiments on spontaneous emission of atomic matter waves open a new window into the behavior of quantum emitters coupled to a waveguide. Here we develop an approach based on infinite products to study this system theoretically, without the need to approximate the band dispersion relation of the waveguide. We solve the system for a one-dimensional array of one, multiple and an infinite number of quantum emitters and compare with the experiments. This leads to a detailed characterization of the decay spectrum, with a family of in-gap bound states, new mechanisms for enhanced Markovian emission different from superradiance, and the emergence of matter-wave polaritons.