Spin wave propagation in corrugated waveguides

TL;DR

This study demonstrates that curvature in corrugated magnonic waveguides significantly enhances spin wave propagation distances, with the potential to tune magnetic responses via geometric design, as shown by experimental microscopy.

Contribution

It introduces a method to control spin wave propagation in magnonic waveguides through surface curvature and modulation amplitude, providing new insights into geometry-dependent magnetic behavior.

Findings

Spin waves propagate 10 times farther in corrugated waveguides without external field.

Moderate modulation amplitudes do not affect spin-wave decay length.

Larger modulation amplitudes cause a linear decrease in decay length.

Abstract

Curvature-induced effects allow us to tailor the static and dynamic response of a magnetic system with a high degree of freedom. We study corrugated magnonic waveguides deposited on a sinusoidally modulated substrate prepared by focused electron beam deposition. The surface curvature in films with thicknesses comparable to the amplitude of modulation locally modifies the contributions of dipolar and exchange energies and results in an effective anisotropy term which can be tuned on-demand based on the exact geometry. We show, by Brillouin light scattering microscopy, that without the presence of an external magnetic field, spin waves propagate over a distance 10$\times$larger in the corrugated waveguide than in the planar waveguide. Further, we analyze the influence of the modulation amplitude on spin-wave propagation and conclude that for moderate modulation amplitudes, the spin-wave decay length is not affected. For larger amplitudes, the decay length decreases linearly with increasing modulation.