Proposal for transduction between microwave and optical photons using $\mathrm{^{167}Er}$-doped yttrium orthosilicate

TL;DR

This paper proposes a high-fidelity microwave-to-optical quantum transducer using $ ext{^{167}Er}$ doped yttrium orthosilicate, enabling efficient reversible conversion of quantum signals at zero magnetic field.

Contribution

It introduces a novel transducer scheme based on dark state protocol in $ ext{^{167}Er}$:YSO operating at zero magnetic field, suitable for superconducting resonators.

Findings

High conversion fidelity demonstrated theoretically.

Zero-field operation reduces losses in superconducting devices.

Feasible microwave and optical transition pathways identified.

Abstract

Efficient transduction devices that reversibly convert optical and microwave quantum signals into each other are essential for integrating different technologies. Rare-earth ions in solids, and in particular Erbium ions, with both optical and microwave addressable transitions are promising candidates for designing transducers. We propose a microwave-to-optical quantum transducer scheme based on the dark state protocol in $\mathrm{^{167}Er}$ doped into yttrium orthosilicate (YSO) at zero external magnetic fields. Zero-field operation is beneficial for superconducting resonators that can incur extra losses in magnetic fields. By calculating the fidelity and efficiency of the transducer, considering the most important imperfections, we show that an efficient conversion is possible with a high fidelity. We also investigate the microwave transitions of $\mathrm{^{167}Er}$:YSO that can be used for the transducer protocol.