Spin-Cherenkov effect in a magnetic nanostrip with interfacial Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates how interfacial Dzyaloshinskii-Moriya interaction influences the excitation of spin waves via the Spin-Cherenkov effect in magnetic nanostrips, revealing reduced threshold velocities and enhanced excitation efficiency.

Contribution

It demonstrates through micromagnetic simulations that DMI reduces the threshold velocity for spin wave excitation in nanostrips, advancing understanding of spin wave control in spintronics.

Findings

DMI lowers the threshold velocity for spin wave excitation.

Coherent spin waves are excited when source velocity exceeds SW propagation speed.

Potential for improved spin wave generation in spintronic devices.

Abstract

Spin-Cherenkov effect enables strong excitations of spin waves (SWs) with nonlinear wave dispersions. The Dzyaloshinskii-Moriya interaction (DMI) results in anisotropy and nonreciprocity of SWs propagation. In this work, we study the effect of the interfacial DMI on SW Cherenkov excitations in permalloy thin-film strips within the framework of micromagnetism. By performing micromagnetic simulations, it is shown that coherent SWs are excited when the velocity of a moving magnetic source exceeds the propagation velocity of the SWs. Moreover, the threshold velocity of the moving magnetic source with finite DMI can be reduced compared to the case of zero DMI. It thereby provides a promising route towards efficient SW generation and propagation, with potential applications in spintronic and magnonic devices.