Hyperfine and Antiferromagnetic Resonances Coupling with Optical Transitions in Rare Earth Crystals for quantum information

The rapid progress in the development of quantum computers is accompanied by the demand for devices enable to connect them into a quantum network.

These devices are transducers that coherently convert microwave radiation into infrared light and vice versa at the single-photon level.

The aim of the project is thus to investigate an innovative transducer scheme based on fully concentrated rare earth crystals with efficiency, bandwidth and suppression of the added noise higher than the current transducers.

By exploiting the large non-linear properties of these crystals in the proximity of their sharp electronic and spin transitions, the microwave field will be mixed with an optical laser field to generate a new optical field that will carry the quantum information previously encoded into the microwave field.

To achieve this goal, carefully selected crystals will be grown and their optical, hyperfine and antiferromagnetic resonances analyzed at mK cryogenic temperatures.

Ultra-narrow tunable lasers and microwave generators coupled with a radiofrequency cavity will provide the optical and microwave fields and the frequency mixing process will be characterized via heterodyne technique.

The rare earth crystals performance will be finally assessed towards implementing microwave to optical transduction in the quantum regime.