  Molecular nanostructures may constitute the fabric of future quantum
technologies, if their degrees of freedom can be fully harnessed. Ideally one
might use nuclear spins as low-decoherence qubits and optical excitations for
fast controllable interactions. Here, we present a method for entangling two
nuclear spins through their mutual coupling to a transient optically-excited
electron spin, and investigate its feasibility through density functional
theory and experiments on a test molecule. From our calculations we identify
the specific molecular properties that permit high entangling power gates under
simple optical and microwave pulses; synthesis of such molecules is possible
with established techniques.
