Observation of Magnonic Band Gaps in Magnonic Crystals with Nopnreciprocal Dispersion Relation

TL;DR

This study investigates how metallization affects magnonic band gaps in yttrium iron garnet-based magnonic crystals, demonstrating nonreciprocal spin wave behavior and potential for advanced magnonic device applications.

Contribution

It provides the first combined theoretical and experimental analysis of nonreciprocal magnonic band gaps in metallized magnonic crystals, revealing their shift and properties.

Findings

Metallization shifts band gaps to higher frequencies.

Nonreciprocal dispersion causes band gap shifts from Brillouin zone edges.

Theoretical models agree with experimental results.

Abstract

An effect of metallization of the magnonic crystal surface on the band gaps formation in the spectra of the surface spin wave (SSW) is studied both theoretically and experimentally. The structures under consideration are one-dimensional magnonic crystals based on yttrium iron garnet with an array of etched grooves with metal screen on the top of the corrugated surface and without it. Due to nonreciprocity of propagation of the SSW the shift of band gap to higher frequency and from the border of the Brillouin zone in presence of conducting overlayer was measured in transmission line experiment. Results of numerical calculations and model analysis are in agreement with experimental data and give further insight into origin of the band gap and properties of the nonreciprocal SSW in metallized magnonic crystals. This gives positive answer to the outstanding question about possibility of detection of magnonic band gaps in the spectra of the spin waves with nonreciprocal dispersion in magnonic crystals and creates potential for new applications and improvements of already existing prototype magnonic devices.