Nonreciprocal State Conversion between Microwave and Optical Photons

TL;DR

This paper proposes a nonreciprocal quantum state conversion scheme between microwave and optical photons using an optomechanical interface, enabling directional control and robust high-fidelity transfer in hybrid quantum networks.

Contribution

It introduces a novel method for achieving nonreciprocal state conversion with phase-controlled optomechanical couplings, functioning as an isolator, circulator, and switch.

Findings

Achieves high-fidelity state conversion under impedance matching.

Demonstrates robustness against mechanical thermal fluctuations.

Enables directional quantum information transfer.

Abstract

Optomechanical quantum interfaces can be utilized to connect systems with distinctively different frequencies in hybrid quantum networks. Here we present a scheme of nonreciprocal quantum state conversion between microwave and optical photons via an optomechanical interface. By introducing an auxiliary cavity and manipulating the phase differences between the linearized optomechanical couplings, uni-directional state transmission can be achieved. The interface can function as an isolator, a circulator, and a two-way switch that routes the input states to a selected output channel. We show that under a generalized impedance matching condition, the state conversion can reach high fidelity and is robust against the thermal fluctuations in the mechanical mode.