Inelastic collisions and density-dependent excitation suppression in a 87Sr optical lattice clock

We observe two-body loss of 3 P087Sr atoms trapped in a one-dimensional optical lattice. We measure loss rate coefficients for atomic samples between 1 and 6 μK 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 1 S0-3 P0 transition as density increases and Rabi frequency decreases, which suggests the presence of strong interactions in our dynamically driven many-body system.