High-Sensitivity Characterization of Magnetic Dynamics Using a Cavity Resonator

Abstract

This thesis explores ferromagnetic resonance (FMR) utilizing an electromagnetic cavity as an alternative to conventional broadband coplanar waveguides. By confining the microwave field, the resonant cavity enhances sensitivity and enables high-resolution probing of magnetic dynamics. This work explores magnon-photon hybridization inside a 3D cylindrical resonant cavity, performs resonance measurements, and analyses linewidths and mode structures to refine techniques for the characterization of ferromagnetic materials. The measurements were performed sing a cylindrical microwave cavity combined with Helmholtz coils to apply a tunable external magnetic field and identify resonance conditions. Data were obtained in both weak and strong coupling regimes, allowing the extraction of relevant magnetic and coupling parameters in all cases. These findings demonstrate the suitability of cavity-based FMR techniques for the investigation of hybrid magnonic systems and their potential applications in spintronic and quantum information technologies.