Multichannel Adjustable Single-Photon Router Based on Large Detuning

Quantum router as a key device in quantum information processing always attracts researchers' attention. This work suggests a single-photon (SP) router based on one bus-waveguide side coupled to numerous Jaynes-Cummings emitters (JCEs). Each JCE connects with a semi-infinite branch waveguide as an output channel. Different from the commonly used scheme that the JCEs are set in the tuning regime, we here let them work in the large-detuning regime. This change brings about the following amazing benefits for the SP router. Firstly, the number of channels can reach more than a thousand. Secondly, the router is adjustable, that is, the SP can be routed into any output channel on demand. Thirdly, the router has a remarkable monochromaticity. Fourthly, such a SP router can also depress the influence of cavity losses and interferential levels in atoms. Finally, the routing probability can reach approximately 100% for each channel by adding a mirror and a phase shifter to the end of the bus waveguide. This work takes the Rydberg atoms 87Rb whose levels can be adjusted by an external electrostatic field as an example to demonstrate the feasibility of the router, which can be applied to quantum informatics.