Spin-motion dynamics with ultracold polar molecules

Due to their strong, long-range, and tunable dipolar interactions, ultracold polar molecules can realize spin-motion models with rich many-body physics. Using a spin encoded in rotational states of fermionic KRb molecules, we demonstrate tuning of Heisenberg XXZ models with electric fields and Floquet engineering of XYZ models with microwave pulse sequences. By controlling motion with optical lattices, we explore highly tunable generalized t-J models. Observing new dynamics and phases predicted for these models also requires low-entropy initial states. We report progress toward producing a deeply degenerate Fermi gas in an isolated 2D layer using a tunable-spacing optical lattice.