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.