Amplification and frequency conversion of spin waves using acoustic waves

TL;DR

This study demonstrates how surface acoustic waves can amplify and convert the frequency of spin waves in magnetic films, enabling flexible control for potential magnonic device applications.

Contribution

It introduces a numerical method for acoustic parametric amplification and frequency conversion of spin waves, advancing hybrid magnonic device design.

Findings

Spin waves can be amplified up to 10 times in amplitude.

Decay length of spin waves can be increased by approximately 2.5 times.

The method enables frequency conversion between low and high modes.

Abstract

We numerically study the acoustic parametric amplification of spin waves using surface acoustic waves (SAW) in a magnetic thin film. First, we illustrate how the process of parametric spin-wave generation using short-waved SAWs with a fixed frequency allows to tune frequencies of the generated spin waves by the applied magnetic field. We further present the amplification of microwave driven spin waves using this method. The decay length and the amplitude of the driven spin waves can be amplified up to approximately 2.5 and 10 times compared to the reference signal, respectively. More importantly, the proposed design can be used as a frequency converter, in which a low (high) frequency spin-wave mode stimulates the excitation of a high (low) frequency mode. Our results pave the way in designing highly flexible and efficient hybrid magnonic device architectures for microwave data transport and processing.