Physics Colloquium with Zoe Yan on Quantum Many-Body Physics

A central challenge of modern physics is understanding the behavior of strongly correlated matter.   Current knowledge of such systems is limited on multiple fronts: experimentally, these materials are often difficult to fabricate in laboratory settings, and numerical simulations become intractable as the number of particles approaches meaningful values.  In the spirit of Feynman, physicists can model diverse phenomena, from high-temperature superconductivity to quantum spin liquids, using analog quantum simulation.  My research explores emergent quantum phenomena in pristine systems made of atoms, molecules, and electromagnetic fields.  In particular, ultracold molecules are a promising platform due to their tunable long-range interactions and large set of internal states. However, this nascent platform requires new experimental techniques to create, control, and probe molecular systems.

I will report on efforts to create ultracold polar molecules, coherently manipulate their internal levels, and demonstrate second-scale coherence times in a molecular ensemble.  To leverage the long-range, anisotropic dipolar interactions, we engineer dipolar collisions in a bulk ensemble using the technique of microwave dressing.  Upon loading polar molecules into a 2D optical lattice, we study dynamics and thermalization in a variety of spin models relevant to quantum magnetism.  Toward that end, we develop a novel readout modality – quantum gas microscopy – to perform site-resolved fluorescence imaging, enabling the measurement of quantum correlations and entanglement.  The techniques presented here establish ultracold molecules as a compelling platform for quantum science and technology.