Eliminating light shifts in single-atom optical traps

TL;DR

This paper introduces a method using temporally alternating beams to eliminate light shifts in single-atom optical traps, enabling broader species manipulation and improving atom loading, cooling, and imaging.

Contribution

A general technique that removes light shift limitations in optical trapping by using alternating beams, applicable to various atomic and molecular species.

Findings

Effective reduction of light shifts in optical tweezers.

Enhanced loading and cooling of single atoms.

Broader applicability to different atomic species.

Abstract

Microscopically controlled neutral atoms in optical tweezers and lattices have led to exciting advances in the study of quantum information and quantum many-body systems. The light shifts of atomic levels from the trapping potential in these systems can result in detrimental effects such as fluctuating dipole force heating, inhomogeneous detunings, and inhibition of laser cooling, which limits the atomic species that can be manipulated. In particular, these light shifts can be large enough to prevent loading into optical tweezers directly from a magneto-optical trap. We present a general solution to these limitations by loading, cooling, and imaging single atoms with temporally alternating beams. Because this technique does not depend on any specific spectral properties, we expect it to enable the optical tweezer method to control nearly any atomic or molecular species that can be laser cooled and optically trapped. Furthermore, we present an analysis of the role of heating and required cooling for single atom tweezer loading.