Efficient Control Of Single-photon Routing In Coupled Waveguide Systems

Quantum communication technology has made breakthrough progress in recent years,and quantum network is an indispensable part of the implementation of quantum communication.Quantum network is mainly composed of quantum nodes and quantum channels.Waveguide is the ideal channel for transmitting optical signals,and photon is the best information carrier,because photon has the characteristics of fast transmission,low dissipation and strong anti-interference ability.Quantum routers are used to control the transmission of light quanta in different quantum channels.Therefore,the quantum routing of light quanta transmission in coupled waveguides has become a research hotspot.In the quantum routing systems proposed in recent years,the routing rate from the primary channel to another channel is less than 0.5,which greatly affects the performance of routers.Therefore,it is necessary to design a quantum routing system with efficient routing and easy control.Based on this,several coupled-waveguide quantum router models are proposed in this paper.By adjusting the relevant parameters,the routing can be effectively controlled.The main contents of this paper are as follows:(1)An efficient router model for broadband is proposed.Two qubits are placed in two parallel waveguides,and a perfect reflection mirror is placed at one end of one of the waveguides.The effect of phase and coupling parameters of qubits on routing is studied to control efficient routing and realize broadband transmission.The quantum routing system designed in this scheme provides a reliable theoretical model for increasing the bandwidth of quantum routing.(2)Two waveguides coupled optomechanical cavities are proposed to construct an efficient quantum routing system model.Two waveguides coupled to two single-mode optomechanical cavity or a two-mode optomechanical cavity are studied.The results show that by effectively controlling the coupling between the waveguide and the optomechanical cavity,the single photon transmission between the two paths can be achieved efficiently in both resonant and non-resonant conditions.Therefore,the system provide potential applications in the design of efficient routers with high routing capability.(3)A three-channel waveguide system for nonreciprocal routing model is proposed.Coupling two qubits in a double-waveguide system with reflective mirror,the effects of the phase,coupling ratio and detuning of qubits on the nonreciprocal transmission efficiency of quantum routers were studied,and based on this,a quantum router with high nonreciprocal routing rate was designed.This scheme provides a useful reference for the design of high efficiency optical filters and diodes in quantum communication.(4)A multi-port photonic filter model is proposed.In the bus waveguide and multi-channel drop waveguide system,a number of qubits are used as media to couple the two waveguides,the multiple routing channel is constructed to realize the filtering function,and the coupling coefficient is adjusted to realize the multi-channel filter with high drop efficiency and low crosstalk.The proposed quantum filter can provide possible applications in wavelength division multiplexing optical communication systems.