Inelastic collisions and density-dependent excitation suppression in a ${}^{87}$Sr optical lattice clock

TL;DR

This study investigates two-body loss and excitation suppression in a ${}^{87}$Sr optical lattice clock, revealing density-dependent effects and strong interactions in a many-body quantum system.

Contribution

It provides the first detailed measurement of loss rates and excitation suppression effects in a ${}^{87}$Sr optical lattice clock under varying density and spin conditions.

Findings

Loss rate coefficients depend on temperature and nuclear spin state.

Suppression of excitation and losses increases with density and decreasing Rabi frequency.

Results align with theoretical calculations of atomic interactions.

Abstract

We observe two-body loss of ${}^3P_0$ ${}^{87}$Sr atoms trapped in a one-dimensional optical lattice. We measure loss rate coefficients for atomic samples between 1 and 6 $\mu$K that are prepared either in a single nuclear-spin-sublevel or with equal populations in two sublevels. The measured temperature and nuclear spin preparation dependence of rate coefficients agree well with calculations and reveal that rate coefficients for distinguishable atoms are only slightly enhanced over those of indistinguishable atoms. We further observe a suppression of excitation and losses during interrogation of the ${}^1S_0$-${}^3P_0$ transition as density increases and Rabi frequency decreases, which suggests the presence of strong interactions in our dynamically driven many-body system.