Observation of Purcell Effect in Electrically Coupled Cavity-Magnet System
Abstract
We report the observation of the Purcell effect in a cavity-metallic magnet hybrid system using electric-field-mediated coupling. In this configuration, microwave-induced axial currents in the microwire induce circular magnetic fields that drive the ferromagnetic resonance (FMR) of the magnetized microwire. Field-dependent transmission and reflection spectroscopies reveal a clear cavity perturbation consistent with the Purcell regime, in which the magnetic loss rate exceeds the light-matter coupling strength. Despite the small magnetic volume (), measurements performed at both room temperature and mK show coupling rates as high as MHz, one order of magnitude stronger than the one expected from conventional coupling at the magnetic antinode. Time-domain ringdown measurements directly show the magnetic-field-dependent modification of the cavity photon lifetime, in agreement with theoretical predictions. These results establish a versatile approach for coupling microwave fields to metallic magnets via geometric and electric-field-mediated interactions, opening new opportunities for hybrid cavity-magnet systems.
Keywords
Cite
@article{arxiv.2508.02946,
title = {Observation of Purcell Effect in Electrically Coupled Cavity-Magnet System},
author = {Italo L. Soares Andrade and Kleber Pirota and Amir O. Caldeira and Francisco Rouxinol},
journal= {arXiv preprint arXiv:2508.02946},
year = {2026}
}