Nonreciprocal Single-Photon Band Structure in a Coupled-Spinning-Resonator chain

TL;DR

This paper investigates how spinning resonators in a chain can create nonreciprocal single-photon band gaps, enabling new photon control devices without external magnetic fields.

Contribution

It introduces a method to generate nonreciprocal and reciprocal single-photon band structures using spinning resonators, bypassing the need for external magnetic fields.

Findings

Two nonreciprocal single-photon band gaps are achieved.

A single photon circulator can be implemented at multiple frequencies.

Reciprocal band structures are possible with uniform rotation.

Abstract

We analyze the single-photon band structure and the transport of a single photon in a one-dimensional coupled-spinning-resonator chain. The time-reversal symmetry of the resonators chain is broken by the spinning of the resonators, instead of external or synthetic magnetic field. Two nonreciprocal single-photon band gaps can be obtained in the coupled-spinning-resonator chain, whose width depends on the angular velocity of the spinning resonator. Based on the nonreciprocal band gaps, we can implement a single photon circulator at multiple frequency windows, and the direction of photon cycling is opposite for different band gaps. In addition, reciprocal single-photon band structures can also be realized in the coupled-spinning-resonator chain when all resonators rotate in the same direction with equal angular velocity. Our work open a new route to achieve, manipulate, and switch nonreciprocal or reciprocal single-photon band structures, and provides new opportunities to realize novel single-photon devices.