Light propagation in atomic Mott Insulators

TL;DR

This paper models light interaction with ultracold atoms in a Mott insulator phase, analyzing polariton behavior and proposing a photon energy lifter device that shifts photon frequency without altering pulse shape or coherence.

Contribution

It introduces a comprehensive quantum model for light propagation in atomic Mott insulators and proposes a novel photon frequency shifting device.

Findings

Polariton dispersion and reflectivity spectra characterized

Photon energy lifter concept demonstrated

Model applicable to finite and semi-infinite geometries

Abstract

We study radiation-matter interaction in a system of ultracold atoms trapped in an optical lattice in a Mott insulator phase. We develop a fully general quantum model, and we perform calculations for a one-dimensional geometry at normal incidence. Both two- and three-level $\Lambda$ atomic configurations are studied. The polariton dispersion and the reflectivity spectra are characterized in the different regimes, for both semi-infinite and finite-size geometries. We apply this model to propose a photon energy lifter experiment: a device which is able to shift the carrier frequency of a slowly travelling wavepacket without affecting the pulse shape nor its coherence.