Transition magnon modes in thin ferromagnetic nanogratings

TL;DR

This study uses micromagnetic simulations to explore how magnon modes in ferromagnetic nanogratings change with different in-plane magnetic field directions, revealing unique mode behaviors between classical geometries.

Contribution

It provides a detailed analysis of magnon mode modifications across all in-plane field directions, highlighting significant differences from classical Damon-Eshbach and backward-volume modes.

Findings

Magnon modes exhibit complex spatial distributions in certain field directions.

Modes have low group velocities in specific magnetic field orientations.

Maximal nonuniform magnetization occurs when the field aligns with the mode center.

Abstract

This work presents micromagnetic simulations in ferromagnetic nanogratings for the full range of directions of an applied in-plane external magnetic field. We focus on the modification of the magnon mode characteristics when the magnetic field orientation is gradually changed between the classical Damon-Eshbach (DE) and backward-volume (BV) geometries. We found that in a specific range of field directions, the magnon mode parameters differ significantly from the parameters in the classical cases, namely, the modes are characterized by complex spatial distributions and have low group velocities. The center of this range corresponds to the direction of the external magnetic field, which gives the maximal nonuniform distribution of the static magnetization in the nanogratings.