Nonreciprocal single-photon router in quantum networks

Abstract

High-efficiency single-photon routing of photon signals between different quantum channels is of great importance for the quantum networks with the ability to coherently transfer quantum states between the desired sender and receiver nodes. We proposed an efficient scheme for realizing quantum routers via multiple semi-infinite coupled-resonator waveguides (CRWs) coupled to cavities nonreciprocally. Numerical results show that with the change of the phase difference value, the quantum routing function of multiple output ports can be realized, in the meantime, the information conversion rate can almost reach 100%. The optimal conditions for these phenomena are obtained by the time-reversal symmetry breaking the nonreciprocal of the single-photon transport. Moreover, we have also described a scalable scheme that can extend the router to an arbitrary number of outputs. Our results pave the way to design high-quality quantum devices based on breaking time-reversal symmetry waveguide-cavity systems.

Dynamic modulated single-photon routing

“…In this regard, a variety of theoretical and experimental efforts have been devoted to the realization and development of single-photon router based on atomic systems, [7][8][9] whispering-gallery resonators, [10][11][12][13] optomechanical systems, [14][15][16][17] cavity (circuit) quantum electrodynamics (QED), [18][19][20][21][22] and waveguide-QED systems. [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] However, most of the previous single-photon router can only work well with a high routing efficiency at the resonant or selected frequency point under the condition that all the system dissipations are completely ignored. [38][39][40] The selected frequency points are usually non-adjustable due to the fact that all the system parameters are constants in previous routing schemes.…”

Directional router and controllable non-reciprocity transmission based on phase and pathway coherence

“…Therefore, it is still a very important problem to study the full transfer rate is 100%, that is, directional routing in quantum routers. Unlike quantum routers coupling single quantum transmitters, the coupling of multiple quantum transmitters with multiple one-dimensional coupled-resonator waveguide can provide many novel phenomena and contribute to the further application of quantum routers [39,40]. In the previous study of non-reciprocal transmission, it was realized through the chiral coupling between the waveguide and the transmitter [24,41].…”

Phase-modulated single-photon nonreciprocal transport and directional router in a waveguide–cavity–emitter system beyond the chiral coupling

“…On the other hand, the router can route single photon from the input port to the desired output port, which has also been studied extensively based on different physical structures, such as waveguide-emitter systems [50][51][52][53][54][55], whispering gallery resonators [56], optomechanical systems [57][58][59], etc. However, how to effectively and conveniently improve the routing efficiency and the operational bandwidth of photon frequencies is still an open field.…”