The anapole moments in disk-form MS-wave ferrite particles

Department of Electrical and Computer Engineering Ben Gurion University of the Negev - Beer Sheva, 84105, Israel

Corresponding author: kmntsk@ee.bgu.ac.il

Received: 2 December 2002
Accepted: 6 November 2003

Abstract

The anapole moments describe the parity-violating parity-odd, time-reversal-even couplings between elementary particles and the electromagnetic (EM) field. Surprisingly, anapole-like moment properties can be found in certain artificially engineered physical systems. In microwaves, ferrite resonators with multi-resonance magnetostatic-wave (MS-wave) oscillations may have sizes 2-4 orders less than the free-space EM wavelength at the same frequency. MS-wave oscillations in a ferrite sample occupy a special place between the “pure” electromagnetic and spin-wave (exchange) processes. The energy density of MS-wave oscillations is not the electromagnetic-wave density of energy and not the exchange energy density. These “microscopic” oscillating objects —the particles— may interact with the external EM fields in a very specific way. To describe such interactions, a mathematical apparatus similar to that of the quantum-mechanical analysis should be used. Because of surface magnetic currents, MS oscillations in ferrite disk resonators become parity violating. The parity-violating couplings between disk-form ferrite particles and the external EM field should be analyzed based on the notion of anapole moment.