Domain wall propagation due to the synchronization with circularly polarized microwaves

TL;DR

This paper demonstrates that circularly polarized microwave magnetic fields can effectively control magnetic domain wall motion in nanowires, revealing two distinct propagation modes and establishing an analogy with spin current-driven motion.

Contribution

It introduces a novel method of controlling domain wall motion using circularly polarized microwave fields, expanding the tools available for spintronics device manipulation.

Findings

Identified rigid and oscillatory domain wall propagation modes.

Established equivalence between microwave-driven and spin current-driven domain wall motion.

Showed microwave frequency acts as a control parameter for domain wall dynamics.

Abstract

Finding a new control parameter for magnetic domain wall (DW) motion in magnetic nanostructures is important in general and in particular for the spintronics applications. Here, we show that a circularly polarized magnetic field (CPMF) at GHz frequency (microwave) can efficiently drive a DW to propagate along a magnetic nanowire. Two motion modes are identified: rigid-DW propagation at low frequency and oscillatory propagation at high frequency. Moreover, DW motion under a CPMF is equivalent to the DW motion under a uniform spin current in the current perpendicular to the plane magnetic configuration proposed recently by Khvalkovskiy et al. [Phys. Rev. Lett. 102, 067206 (2009)], and the CPMF frequency plays the role of the current.