Slow-wave based magnonic diode

TL;DR

This paper presents the design and experimental demonstration of a magnonic diode that allows unidirectional spin wave transmission using dipolar interactions in a ferromagnetic bilayer, advancing wave-based computing technologies.

Contribution

It introduces a novel magnonic diode leveraging dipolar nonreciprocity in a bilayer system, combining experimental realization with micromagnetic simulations.

Findings

Achieved unidirectional spin wave propagation with low group velocity in one direction.

Demonstrated diode behavior using Brillouin light scattering and spin-wave spectroscopy.

Validated design through micromagnetic simulations.

Abstract

Spin waves, the collective excitations of the magnetic order parameter, and magnons, the associated quasiparticles, are envisioned as possible data carriers in future wave-based computing architectures. On the road towards spin-wave computing, the development of a diode-like device capable of transmitting spin waves in only one direction, thus allowing controlled signal routing, is an essential step. Here, we report on the design and experimental realization of a microstructured magnonic diode in a ferromagnetic bilayer system. Effective unidirectional propagation of spin waves is achieved by taking advantage of nonreciprocities produced by dynamic dipolar interactions in transversally magnetized media, which lack symmetry about their horizontal midplane. More specifically, dipolar-induced nonreciprocities are used to engineer the spin-wave dispersion relation of the bilayer system so that the group velocity is reduced to very low values for one direction of propagation, and not for the other, thus producing unidirectional slow spin waves. Brillouin light scattering and propagating spin-wave spectroscopy are used to demonstrate the diode-like behavior of the device, the composition of which was previously optimized through micromagnetic simulations. simulations.