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

Abstract

Ultracold polar molecules are promising candidate qubits for quantum computing and quantum simulations. Their long-lived molecular rotational states form robust qubits and the long-range dipolar interaction between molecules provides quantum entanglement. Here, we demonstrate dipolar spin-exchange interactions between single CaF molecules trapped in an optical tweezer array. We realize the spin-1/2 quantum XY model by encoding an effective spin-1/2 system into the rotational states of the molecules, and use it to generate a Bell state through an iSWAP operation. Conditioned on the verified existence of molecules in both tweezers at the end of the measurement, we obtain a Bell state fidelity of 0.89(6). Employing interleaved tweezer arrays, we demonstrate single site molecular addressability.