Operating Single-Photon Circulator by Spinning Optical Resonators

TL;DR

This paper proposes a novel single-photon circulator using spinning optical resonators, enabling controlled photon routing at multiple frequencies and overcoming backscattering issues through resonator rotation.

Contribution

It introduces a four-port single-photon circulator based on spinning resonators, demonstrating frequency-specific circulation and backscattering suppression.

Findings

Photon circulation occurs at specific frequency points when resonators rotate at different velocities.

Equal and opposite angular velocities of resonators enable circulation at two distinct frequencies.

Rotating resonators can restore circulation suppressed by backscattering.

Abstract

A circulator is one of the crucial devices in quantum networks and simulations. We propose a four-port circulator that regulate the flow of single photons at muti-frequency points by studying the coherent transmission of a single photon in a coupled system of two resonators and two waveguides. When both resonators are static or rotate at the same angular velocity, single-photon transport demonstrates reciprocity; however, when the angular velocities differ, four distinct frequency points emerge where photon circulation can occur. In particular, when the angular velocities of the two resonators are equal and opposite, there are two different frequency points where photon circulation can be achieved, and there is a frequency point where a single photon input from any waveguide can be completely routed to the other waveguide. Interestingly, by rotating the two resonators, the single-photon circulation suppressed by the internal defect-induced backscattering can be restored.