Nonreciprocity in microwave optomechanical circuits

TL;DR

This paper reviews microwave optomechanical circuits that achieve nonreciprocity, offering potential for integrated quantum devices with low noise, by explaining the underlying physics and future applications.

Contribution

It introduces a gyrator-based framework to understand nonreciprocity in microwave optomechanical systems and discusses their potential for quantum-limited nonreciprocal devices.

Findings

Gyrator-based model explains nonreciprocity origin.

Optomechanical circuits can be extended to circulators.

Potential to reach quantum-limited noise performance.

Abstract

Nonreciprocal devices such as isolators and circulators are necessary to protect sensitive apparatus from unwanted noise. Recently, a variety of alternatives were proposed to replace ferrite-based commercial technologies, with the motivation to be integrated with microwave superconducting quantum circuits. Here, we review isolators realized with microwave optomechanical circuits and present a gyrator-based picture to develop an intuition on the origin of nonreciprocity in these systems. Such nonreciprocal optomechanical schemes show promise as they can be extended to circulators and directional amplifiers, with perspectives to reach the quantum limit in terms of added noise.