Site-resolved measurements of real and momentum space correlations of ultracold molecules in an optical lattice

Ultracold molecules are prime candidates for the quantum simulation of many-body physics, owing to their long-range interactions and rich set of long-lived internal states.  Here, we present our approach to prepare ultracold NaRb molecules from the Feshbach association of dual-species 2D condensates loaded into an optical lattice, before coherently transferring them to the molecular ground state via STIRAP. These are dissociated back into atoms and imaged using a quantum gas microscope for the site-resolved detection of the molecules. This enables us to probe multi-point correlations between the molecules that emerge due to either quantum statistics or interactions. We use this technique to make the first observation of the Hanbury Brown and Twiss effect with molecules by detecting their spatial bunching after a long-time of flight [1]. Additionally, starting from NaRb molecules in the absolute ground state, we excite microwave transitions to prepare superpositions with the first excited rotational molecular state, thereby turning on strong dipolar interactions.  We measure long many-body limited rotational coherence times and use the microscope to study the dynamics of molecule pair correlations in the 2D quantum XY spin model.

[1] J. S. Rosenberg et al., arXiv:2111.09426.