Nonlinear erasing of propagating spin-wave pulses in thin-film Ga:YIG

TL;DR

This study demonstrates nonlinear erasing of propagating spin-wave pulses in a gallium-substituted yttrium iron garnet film, enabling complex temporal logic operations for magnonic information processing.

Contribution

It introduces a method to control spin-wave interactions via nonlinear effects in Ga:YIG, facilitating all-magnonic erasing of signals for advanced magnonic devices.

Findings

Time-separated spin-wave pulses can be excited and manipulated.

Higher group velocity pulses can erase slower pulses through nonlinear interaction.

The process enables potential applications in neuromorphic computing.

Abstract

Nonlinear phenomena are key for magnon-based information processing, but the nonlinear interaction between two spin-wave signals requires their spatio-temporal overlap which can be challenging for directional processing devices. Our study focuses on a gallium-substituted yttrium iron garnet film, which exhibits an exchange-dominated dispersion relation and thus provides a particularly broad range of group velocities compared to pure YIG. Using time- and space-resolved Brillouin light scattering spectroscopy, we demonstrate the excitation of time-separated spin-wave pulses at different frequencies from the same source, where the delayed pulse catches up with the previously excited pulse and outruns it due to its higher group velocity. By varying the excitation power of the faster pulse, the outcome can be finely tuned from a linear superposition to a nonlinear interaction of both pulses, resulting in a full attenuation of the slower pulse. Therefore, our findings demonstrate the all-magnonic erasing process of a propagating magnonic signal, which enables the realization of complex temporal logic operations with potential application, e.g., in inhibitory neuromorphic functionalities.