Photonic crystal optics in cold atomic gases

TL;DR

This paper explores how light propagates through cold atomic gases with periodic density, demonstrating photonic crystal-like effects including negative refraction, and shows how to excite and split refracting modes using semi-adiabatic propagation.

Contribution

It introduces a novel approach to control light in cold atomic gases with periodic structures, including an optical analog of the quantum adiabatic theorem and mode splitting techniques.

Findings

Demonstrated negative refraction in cold atomic gases

Derived an optical analog of the quantum adiabatic theorem

Showed mode excitation and splitting at accessible gas densities

Abstract

We describe propagation of light in a gas with periodic density modulation, demonstrating photonic-crystal-like refraction with negative refraction angles. We address the role of poorly defined boundaries and damping, and derive an optical analog of the quantum adiabatic theorem. For Cs atoms in an optical lattice, we show that relying on semi-adiabatic propagation one can excite and spatially split positively and negatively refracting modes at experimentally available gas densities.