Phase-tunable single-photon routing between two waveguides with double two-level atoms
Liming Yang, Zhonghua Zhu, Yi‐Qi Zhang, Yi-Feng Chai · Laser Physics Letters · 2025
Abstract We investigate single-photon quantum routing composed of double two-level atoms coupled to two infinite waveguides. By introducing local coupling phases at atom-waveguide connecting points, we engineer asymmetric atom-waveguide interactions, which enables the directional control of photon propagation for achieving high-efficiency quantum routing. Using the real-space approach, we derived exact expressions of the single-photon scattering amplitudes, allowing for a comprehensive analysis of the routing dynamics. For both identical and non-identical atomic configurations, we systematically explored the conditions for achieving perfect photon transfer. Our results demonstrate that complete photon transfer can be realized by precisely tuning the coupling phases, the accumulated phase and atomic frequencies. This work provides a theoretical foundation for developing high-efficiency quantum routers with potential applications in quantum networks and photonic quantum information processing.