YIG/CoFeB bilayer magnonic diode

TL;DR

This paper introduces a YIG/CoFeB bilayer magnonic diode that leverages non-reciprocal spin-wave propagation for unidirectional signal transmission, combining experimental and simulation results to demonstrate its potential for wave-based computing.

Contribution

It presents the first experimental demonstration of a YIG/CoFeB bilayer magnonic diode utilizing dipolar coupling for non-reciprocal spin-wave propagation.

Findings

Unidirectional propagation of MSSW confirmed by BLS measurements.

Significant suppression of backscattered waves observed.

Numerical simulations support experimental results.

Abstract

We demonstrate a magnonic diode based on a bilayer structure of Yttrium Iron Garnet (YIG) and Cobalt Iron Boron (CoFeB). The bilayer exhibits pronounced non-reciprocal spin-wave propagation, enabled by dipolar coupling and the magnetic properties of the two layers. The YIG layer provides low damping and efficient spin-wave propagation, while the CoFeB layer introduces strong magnetic anisotropy, critical for achieving diode functionality. Experimental results, supported by numerical simulations, show unidirectional propagation of Magnetostatic Surface Spin Waves (MSSW), significantly suppressing backscattered waves. This behavior was confirmed through wavevector-resolved and micro-focused Brillouin Light Scattering measurements and is supported by numerical simulations. The proposed YIG/SiO$_2$/CoFeB bilayer magnonic diode demonstrates the feasibility of leveraging non-reciprocal spin-wave dynamics for functional magnonic devices, paving the way for energy-efficient, wave-based signal processing technologies.