Designable single-photon quantum routings with atomic mirrors

Abstract

Quantum routers are the necessary elements of the quantum information network, and thus their routing capabilities are particularly important. With the atomic mirrors robustly controlling the reflected or transmitted coefficient of the waveguide photon, we show that a two-level atom can be served as an ideal quantum router to redirect a single photon from the input waveguide into the output waveguides (OWGs) with designable probabilities, e.g., $100%$ for one OWG, $1/2$ to one of the two OWGs, and $1/3$ to one of the three OWGs, etc.. The influence of the atomic dissipations on the routing capability is also discussed.