Dipolar switching for robust quantum computation with polar molecules

We propose to use a new platform -- ultracold polar molecules -- for quantum computing with switchable interactions. The on/off switch is accomplished by selective excitation of one of the ``0'' or ``1'' qubits -- long-lived molecular states -- to an ``excited'' molecular state with a considerably different dipole moment. We describe various schemes based on this switching of dipolar interactions where the selective excitation between ground and excited states is accomplished via optical, micro-wave, or electric fields. We also generalized the schemes to take advantage of the {\it dipole blockade} mechanism when dipolar interactions are very strong. These schemes can be realized in several recently proposed architectures.