Dipole-dipole frequency shifts in multilevel atoms

TL;DR

This paper analyzes how dipole-dipole interactions affect frequency shifts in multilevel atoms used in atomic clocks, revealing suppression effects and non-classical phenomena that can improve clock accuracy.

Contribution

It provides a detailed calculation of dipolar frequency shifts considering atomic multilevel structures, challenging the two-level approximation in certain transitions.

Findings

Suppression of dipolar frequency shifts in specific transitions

Emergence of non-classical effects under relevant experimental conditions

Implications for enhancing optical lattice and tweezer clock accuracy

Abstract

Dipole-dipole interactions lead to frequency shifts that are expected to limit the performance of next-generation atomic clocks. In this work, we compute dipolar frequency shifts accounting for the intrinsic atomic multilevel structure in standard Ramsey spectroscopy. When interrogating the transitions featuring the smallest Clebsch-Gordan coefficients, we find that a simplified two-level treatment becomes inappropriate, even in the presence of large Zeeman shifts. For these cases, we show a net suppression of dipolar frequency shifts and the emergence of dominant non-classical effects for experimentally relevant parameters. Our findings are pertinent to current generations of optical lattice and optical tweezer clocks, opening a way to further increase their current accuracy, and thus their potential to probe fundamental and many-body physics.