Dipolar interaction in an array of individually-controlled molecules

Ultracold polar molecules can interact at long-range via electric dipole-dipole interactions, which can be controlled to entangle distant molecules by coherently coupling their rotational states. Such capability, together with many available rotational states, makes polar molecules attractive for quantum science applications. I will discuss our platform of molecular qubits, where optical tweezer arrays of NaCs molecules are created by adiabatically assembling their constituent atoms. By tuning the tweezer polarization to a specific 'magic' ellipticity, we eliminate trap-induced differential light shifts, allowing us to encode a qubit in a pair of rotational states with a coherence time of up to 250 ms. We then observe fast dipolar interactions between adjacent molecules. We achieve kHz interaction at an inter-particle distance of 1.6 um, opening many opportunities in quantum computing and quantum simulation on our platform.