Highly efficient optical Fredkin gate with weak nonlinearities and classical information feed-forward
Meng-Zheng Zhu, Xin-Guo Yin · Journal of the Optical Society of America B · 2013
A scheme is proposed to implement the optical quantum Fredkin gate with weak nonlinearities and feed-forward. The distinctive feature of the present scheme is that the present Fredkin gate has four sets of possible output ports, and the total success probability for each set of the output ports is near 1/4 without ancillary single-photon. The present scheme requires nonlinear strength of the order of 10−3 and mean photon number of the probe coherent beam of the order of 106 so that the discrimination error probability does not exceed 10−4. These features show that it is still possible to operate in the regime of weak cross-Kerr nonlinearities, and the amplitude of the probe coherent beam is physically reasonable with current technology. These facts make us more confident in the feasibility of the proposed scheme.