Bidirectional Highly-Efficient Quantum Routing In A T-Bulge-Shaped Waveguide*

Quantum routing in a T-bulge-shaped waveguide system coupled with a driven cyclic three-level atom and a two-level atom is investigated theoretically. By employing the discrete-coordinate scattering method, exact expressions of the transport coefficients along three ports of the waveguide channels are derived. Our results show that bidirectional high transfer-rate single-photon routing between two channels can be effectively implemented, with the help of the effective potential generated by two atoms and the external driving. Moreover, multiple band zero-transmission emerges in the scattering spectra, arising from the quantum interferences among photons scattered by the boundary and the bulged resonators. The proposed system may suggest an efficient duplex router with filtering functions.