Abstract: Optical tweezer arrays of laser-cooled molecules are an emerging platform for quantum science, combining the rich internal structure of molecules with the versatile microscopic control and detection capabilities of optical tweezers. In recent years, our lab has helped push the frontier of quantum control in this platform, demonstrating high-fidelity single-molecule imaging and state preparation, coherent control at both the single and two molecule level, and deterministic entanglement between individually prepared molecules.
In this talk, I will present recent investigations in our lab which open the door to investigating quantum many-body spin models and to preparing metrologically useful states in ultracold molecular tweezer arrays. Technical advances such as measurement-enhanced state preparation now allow us to prepare defect-free and internally pure mesoscopic arrays of ~10 molecules, which we use to simulate tunable XYZ spin models realized through Floquet engineering of dipolar interactions. I will discuss studies of magnon dynamics in this system, including quantum walks of single spins, two-magnon bound states, and the coherent creation and annihilation of spin pairs. Then, I will highlight very recent work demonstrating spin squeezing in molecules for the first time, where we directly observe over 2dB of metrological gain. I will also describe how spin-squeezing -- created with interacting rotational states -- can be transduced to long-lived non-interacting hyperfine states, where they maintain practical advantage for ~100ms. Time permitting, I will conclude with recent developments on scaling toward larger arrays of ~100 molecules.