Interaction of magnetic-dipolar modes with microwave-cavity electromagnetic fields

TL;DR

This paper explores the unique interactions between magnetic-dipolar modes in ferrite disk resonators and microwave cavity electromagnetic fields, revealing special behaviors, energy characteristics, and experimental evidence of eigen-electric-moment oscillations.

Contribution

It presents new insights into the interaction mechanisms of MS oscillations with cavity fields and provides experimental evidence for eigen-electric-moment oscillations in ferrite disks.

Findings

Unique geometrical effects in thin-film ferrite disks

Resonant absorption due to staircase demagnetization energy

Experimental evidence of eigen-electric-moment oscillations

Abstract

We discuss the problem of magnetic-dipolar oscillations combined with microwave resonators. The energy density of magnetic-dipolar or magnetostatic (MS) oscillations in ferrite resonators is not the electromagnetic-wave density of the energy and not the exchange energy density as well. This fact reveals very special behaviors of the geometrical effects. Compared to other geometries, thin-film ferrite disk resonators exhibit very unique interactions of MS oscillations with the cavity electromagnetic fields. MS modes in a flat ferrite disk are characterized by a complete discrete spectrum of energy levels. The staircase demagnetization energy in thin-film ferrite disks may appear as noticeable resonant absorption of electromagnetic radiation. Our experiments show how the environment may cause decoherence for magnetic oscillations. Another noticeable fact is experimental evidence for eigen-electric-moment oscillations in a ferrite disk resonator.