# Reversible tuning of omnidirectional band gaps in two-dimensional magnonic crystals by magnetic field and in-plane squeezing

## TL;DR

This paper demonstrates how applying magnetic field and in-plane squeezing to a two-dimensional magnonic crystal can reversibly tune omnidirectional magnonic band gaps, enabling adaptable magnonic devices.

## Contribution

It introduces a method to reversibly tune magnonic band gaps in 2D magnonic crystals through magnetic field and structural squeezing effects.

## Key findings

- Squeezing alters demagnetizing field and confinement, creating band gaps.
- Propagational effects explain k-dependent mode softening.
- Designs allow control over band gap width, position, and response to magnetic field changes.

## Abstract

By means of the plane wave method, we study nonuniform, i.e., mode- and k-dependent, effects in the spin-wave spectrum of a two-dimensional bicomponent magnonic crystal. We use the crystal based on a hexagonal lattice squeezed in the direction of the external magnetic field wherein the squeezing applies to the lattice and the shape of inclusions. The squeezing changes both the demagnetizing field and the spatial confinement of the excitation, which may lead to the occurrence of an omnidirectional magnonic band gaps. In particular, we study the role played by propagational effects, which allows us to explain the k-dependent softening of modes. The effects we found enabled us not only to design the width and position of magnonic band gaps, but also to plan their response to a change in the external magnetic field magnitude. This allows the reversible tuning of magnonic band gaps, and it shows that the studied structures are promising candidates for designing magnonic devices that are tunable during operation.