Magnetic Domain Wall Motion due to AC Bias-Driven Resonances

TL;DR

This paper demonstrates that AC biases can resonantly drive magnetic domain walls through phase synchronization, enabling low-power operation and revealing a phase transition similar to Walker breakdown.

Contribution

It introduces the concept of AC bias-driven domain wall motion via phase locking, expanding understanding beyond traditional DC bias effects.

Findings

DW velocity proportional to AC frequency, independent of bias strength

Identification of phase locking-unlocking transition in DW motion

Resonant driving of DWs through internal angle synchronization

Abstract

Most of the existing researches on the dynamics of a domain wall (DW) have focused on the effect of DC biases, where the induced velocity is determined by the bias strength. Here we show that AC biases such as a field or a current are also able to move a DW via synchronization between the DW angle and the phase of the AC bias. The resulting DW velocity is proportional to the driving frequency of the AC bias, but independent of the bias strength, offering potentially low-power operations of DW devices. The AC-bias-driven DW motion is shown to exhibit a phase locking-unlocking transition, a critical phenomenon akin to the Walker breakdown of a DC-bias-driven DW motion. Our work shows that a DW can be driven resonantly by synchronizing its angle to AC biases, shedding a light on hitherto overlooked utility of internal degree of freedom for driving magnetic textures.