Developing schemes for efficient and broadband frequency conversion of quantum signals is an ongoing challenge in the field of modern quantum information. The coherent conversion between microwave and optical signals is an especially important milestone towards long-distance quantum communication. In this work, we propose a two-stage conversion protocol, employing a resonant interaction between magnetic and mechanical excitations as a mediator between microwave and optical photons. Based on estimates for the coupling strengths under optimized conditions for yttrium iron garnet, we predict close to unity conversion efficiency without the requirement of matching cooperativities. We predict a conversion bandwidth in the regions of largest efficiency of the order of magnitude of the coupling strengths that can be further increased at the expense of reduced conversion efficiency.

• Received 10 May 2022
• Revised 18 July 2022
• Accepted 1 September 2022

DOI:https://doi.org/10.1103/PhysRevApplied.18.044059

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by the Max Planck Society.

Published by the American Physical Society