Abstract
We describe and operate a spin-magnetometer based on the phase modulation of cavity magnon polaritons. In this scheme a rf magnetic field is detected through the sidebands it induces on a pump, and the experimental configuration allows for a negligible pump noise and a high-frequency readout. The demonstrator setup, based on a copper cavity coupled to an yttrium iron garnet sphere hybrid system, reached a sensitivity of at 220 MHz, evading the pump noise and matching the theoretical predictions. An optimized setup can attain a rf magnetic field sensitivity of about at room temperature. An orders of magnitude improvement is expected at lower temperatures, making this instrument one of the few magnetometers accessing the subfemtotesla limit.
- Received 30 September 2020
- Revised 2 August 2021
- Accepted 2 September 2021
DOI:https://doi.org/10.1103/PhysRevApplied.16.034036
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