Nonreciprocal Control of the Speed of Light Using Cavity Magnonics

TL;DR

This paper demonstrates a nonreciprocal method to control the speed of microwave light using cavity magnonics, enabling directional switching between slow and fast light for advanced signal processing applications.

Contribution

It introduces a non-reciprocal EIT effect via dissipative magnon-photon coupling, allowing directional control of light speed in microwave cavities, which is a novel approach.

Findings

Reversal of magnetic field switches between slow and fast light.

Nonreciprocal control achieved at the same frequency with comparable amplitude.

Potential applications in microwave communication and quantum information processing.

Abstract

We demonstrate nonreciprocal control of the speed of light by sending a microwave pulse through a cavity magnonics device. In contrast to reciprocal group velocity controlled by conventional electromagnetically induced transparency (EIT) effect, incorporating dissipative magnon-photon coupling establishes a non-reciprocal EIT effect, allowing slow and fast light propagation in opposite directions at the same frequency with comparable amplitude. Remarkably, reversing the magnetic field enables a directional switch between non-reciprocal fast and slow light. This discovery may offer new possibilities for pulse time regulation in microwave signal communications, neuromorphic computing, and quantum signal processing.