Single-photon routing via multi-channel interference in coupled-cavity waveguides with cyclic transitions and an atomic-like mirror

Abstract

We propose a quantum routing scheme based on coupled-cavity waveguides incorporating a three-level quantum dot with classical-field-driven cyclic transitions and an additional two-level quantum dot acting as an atomic-like mirror. In contrast to conventional single-emitter or simple multi-emitter configurations, where the photon transfer rate is typically limited to 0.5, the proposed system introduces an additional interference pathway via the auxiliary quantum dot, enabling enhanced routing controllability. By employing discrete scattering theory, we analytically derive the transmission, reflection, and inter-waveguide transfer coefficients and systematically investigate their dependence on the Rabi frequency, emitter–waveguide coupling strength, detuning, and incident direction. The results show that the interplay between dressed-state formation and multi-channel interference significantly modifies the spectral response of the system. In particular, the transfer rate into the secondary waveguide can exceed 0.5 under appropriate conditions, demonstrating a clear advantage over previously reported schemes. These findings provide a physically transparent mechanism for achieving flexible and efficient single-photon routing and offer theoretical guidance for the design of integrated quantum photonic devices, such as quantum routers, beam splitters, and on-chip quantum network components.