Physical Origin and Generic Control of Magnonic Band Gaps of Dipole-Exchange Spin Waves in Width-Modulated-Nanostrip Waveguides

TL;DR

This paper introduces a novel planar magnonic-crystal waveguide structure made of a single magnetic material, where width modulation controls the band gaps of dipole-exchange spin waves, enabling potential broadband GHz spin-wave filters.

Contribution

It demonstrates for the first time how width modulation in nanostrip waveguides can control magnonic band gaps, combining experimental design with micromagnetic and analytical analysis.

Findings

Multiple wide magnonic band gaps of ~10 GHz are achieved.

Periodic width modulation effectively controls the band gap positions.

The study provides parameters for designing broadband spin-wave filters.

Abstract

We report, for the first time, on a novel planar structure of magnonic-crystal waveguides, made of a single magnetic material, in which the allowed and forbidden bands of propagating dipole-exchange spin-waves can be manipulated by the periodic modulation of different widths in thin-film nanostrips. The origin of the presence of several magnonic wide band gaps and the crucial parameters for controlling those band gaps of the order of ~10 GHz are found by micromagnetic numerical and analytical calculations. This work can offer a route to the potential application to broad-band spin-wave filters in the GHz frequency range.