On demand single photon-driven controlled-NOT gate

This paper describes a controlled-NOT gate operating for the first time with single photons, in this case excited from a single InAs quantum dot in a pillar microcavity. By guiding the emission from the neutral exciton into a semiconductor integrated optical circuit, the single photon nature (g(2)(0) = 0.013) was confirmed and it was shown that consecutive photons are indistinguishable (Hong-Ou-Mandel interference visibility = 0.72). Then, using a more complex circuit with optimised 1/2 and 1/3 directional couplers, it is show that controlled-NOT gate operation has a success probability of 0.75.