Resolved atomic interaction sidebands in an optical clock transition

TL;DR

This paper reports the observation of resolved atomic interaction sidebands in an optical clock transition of strontium atoms confined in a 2D optical lattice, revealing strong interaction effects and potential for precise spectroscopy.

Contribution

It demonstrates the experimental detection of interaction sidebands in a 2D lattice and links their emergence to atomic confinement and interaction effects, advancing understanding of collisional shifts.

Findings

Resolved ISB observed in strontium optical lattice

ISB disappear when confinement is relaxed

Lower temperatures predicted to produce narrower ISB

Abstract

We report the observation of resolved atomic interaction sidebands (ISB) in the ${}^{87}$Sr optical clock transition when atoms at microkelvin temperatures are confined in a two-dimensional (2D) optical lattice. The ISB are a manifestation of the strong interactions that occur between atoms confined in a quasi-one-dimensional geometry and disappear when the confinement is relaxed along one dimension. The emergence of ISB is linked to the recently observed suppression of collisional frequency shifts in [1]. At the current temperatures, the ISB can be resolved but are broad. At lower temperatures, ISB are predicted to be substantially narrower and usable as powerful spectroscopic tools in strongly interacting alkaline-earth gases.