Double and negative reflection of cold atoms in non-Abelian gauge potentials

TL;DR

This paper investigates how cold atoms reflect in non-Abelian gauge potentials created by laser configurations, revealing unique phenomena like negative and split reflections that could impact future atom optics technologies.

Contribution

It demonstrates the occurrence of negative and split atom reflections in non-Abelian gauge potentials, a novel finding in atom optics.

Findings

Atoms exhibit negative reflection under certain conditions.

Incident waves can split into two reflected waves.

Reflection behavior depends on the angle of incidence.

Abstract

Atom reflection is studied in the presence of a non-Abelian vector potential proportional to a spin-1/2 operator. The potential is produced by a relatively simple laser configuration for atoms with a tripod level scheme. We show that the atomic motion is described by two different dispersion branches with positive or negative chirality. As a consequence of that, atom reflection shows unusual features, since an incident wave may split into two reflected ones at a barrier, an ordinary specular reflection, and an additional non-specular one. Remarkably, the latter wave can exhibit negative reflection and may become evanescent if the angle of incidence exceeds a critical value. These reflection properties are crucial for future designs in non-Abelian atom optics.