Princeton University Donald R. Hamilton Colloquium Series

Abstract: Optical tweezer arrays of molecules are an emerging platform for quantum science. They combine the richness of molecules - both in their internal structure and interactions - with the microscopic control offered by optical tweezers, opening new possibilities in quantum information processing, quantum simulation, and quantum metrology. In this talk, I will describe our group’s work on developing optical tweezer arrays of laser-cooled polar molecules and using them to explore several areas in quantum science. I will first discuss several of our advances in preparing, controlling, and detecting single molecules. I will then describe how we utilize electric dipolar interactions to realize two-qubit gates and deterministically entangle pairs of molecules. Next, I will present two investigations using 1D arrays of interacting molecules. The first is a series of quantum simulation experiments in which we realize quantum spin models and study their non-equilibrium dynamics. Specifically, we engineer tunable dipolar spin models and study how spin excitations, i.e. magnons, propagate, bind together, and are coherently created and annihilated in pairs. The second investigation concerns quantum-enhanced metrology. 

I will describe how we create and probe spin-squeezed states - a class of metrologically useful entangled states - in molecules for the first time. I will then present site-resolved measurements of these states that not only show how quantum noise is suppressed but also reveal strong non-classical correlations, including bipartite entanglement and Einstein-Podolsky-Rosen steering. Finally, if time permits, I will report preliminary work on scaling up these arrays.