Dipolar spin-exchange and entanglement between molecules in an optical tweezer array

Due to their intrinsic electric dipole moments and rich internal structure, ultracold polar molecules are promising candidate qubits for quantum computing and quantum simulations. Their long-lived molecular rotational states form robust qubits while the long-range dipolar interaction between molecules provides quantum entanglement. Using a molecular optical tweezer array, single molecules can be moved and separately addressed using optical and microwave fields. In this talk, I will discuss our recent work on demonstration of dipolar spin-exchange interactions between single CaF molecules trapped in an optical tweezer array. We realize the spin-$frac{1}{2}$ quantum XY model by encoding an effective spin-$frac{1}{2}$ system into the rotational states of the molecules, and use it to demonstrate a two-qubit (two-molecule) quantum gate. Conditioned on the verified existence of molecules in both tweezers at the end of the measurement, we obtain a Bell state fidelity of 0.87(6). Employing interleaved tweezer arrays, we demonstrate high fidelity single site molecular addressability.