Chiral single-photon switch-assisted quantum logic gate with a nitrogen-vacancy center in a hybrid system

We propose what we believe is a novel proposal for realizing a quantum C-NOT logic gate, through fabricating an interesting hybrid device with a chiral photon-pulse switch, a single nitrogen-vacancy (NV) center, and an optical microcavity. Three major different practical routes on realizing a chiral photon emitter are discussed, which can implement a chiral control unit via the nonreciprocal emitter-photon interactions, so-called "propagation-direction-dependent" emission. With the assistance of dichromatic microwave driving fields, we carry out the relevant C-NOT operations by engineering the interactions on a single NV spin in a cavity. We note that this logic gate is robust against practical noise and experimental imperfection, and this attempt may evoke wide and fruitful applications in quantum information processing. (C) 2021 Chinese Laser Press