Single-photon nonreciprocal transport in one-dimensional coupled-resonator waveguides

摘要

We study the transport of a single photon in two coupled one-dimensionalsemi-infinite coupled-resonator waveguides (CRWs), in which both end sides arecoupled to a dissipative cavity. We demonstrate that a single photon cantransfer from one semi-infinite CRW to the other nonreciprocally. Based on suchnonreciprocity, we further construct a three-port single-photon circulator by aT-shaped waveguide, in which three semi-infinite CRWs are pairwise mutuallycoupled to each other. The single-photon nonreciprocal transport is induced bythe breaking of the time-reversal symmetry and the optimal conditions for thesephenomena are obtained analytically. The CRWs with broken time-reversalsymmetry will open up a kind of quantum devices with versatile applications inquantum networks.