Scattering of exchange spin waves from regions of modulated magnetization

TL;DR

This paper studies how spin waves reflect and transmit in ferromagnetic films with modulated magnetization, revealing resonance effects similar to quantum phenomena, with implications for reconfigurable magnonic devices.

Contribution

It provides analytical and simulation insights into spin wave transmission resonances caused by magnetization modulation, advancing understanding for magnonic device design.

Findings

Identification of transmission resonances depending on region width and excitation energy

Resemblance to the quantum Ramsauer-Townsend effect in spin wave propagation

Potential for dynamic control in reconfigurable magnonic devices

Abstract

We investigate the reflection coefficient of spin waves propagating in an ultra-thin ferromagnetic film with regions where saturation magnetization is modulated. We find analytically and using micromagnetic simulations that there are transmission resonances that depend on the width of the regions and on the energy of excitation. Our results resemble the quantum mechanical Ramsauer-Townsend effect in which an electron with certain energies can propagate above a potential field without scattering. Our findings are useful for reconfigurable magnonic devices where the saturation magnetization can be dynamically controlled via a thermal landscape.