Simple schemes for universal quantum gates with nitrogen-vacancy centers in diamond

We propose efficient schemes for universal quantum gates with the photon polarization states and electron spin states of nitrogen-vacancy (NV) centers in diamond embedded in optical microcavity. A hybrid polarization-spin controlled-NOT gate and a two-qubit controlled phase gate between NV centers in separated cavities are demonstrated in the weak-coupling regime without complex devices or interaction. The gates presented here are deterministic and can be applied directly to a variety of quantum information processing tasks. The feasibility analyses show that our schemes can be accomplished with high fidelity under current technologies and have wide potential applications in quantum communication and computation fields. (C) 2013 Optical Society of America