Manipulating domain wall chirality by current pulses in Permalloy/Ir nanostrips

TL;DR

This study demonstrates that nanosecond current pulses can reversibly manipulate the chirality of magnetic domain walls in Permalloy/Ir nanostrips, with the Oersted magnetic field playing a stabilizing role during current-induced domain wall motion.

Contribution

It reveals that current pulses can control domain wall chirality in bilayer nanostrips, highlighting the role of Oersted fields in stabilizing magnetic configurations.

Findings

Reversible switching of domain wall chirality with current pulses.

Oersted field stabilizes transverse domain walls during current application.

Current densities used are comparable to those for domain wall motion.

Abstract

Using magnetic force microscopy and micromagnetic simulations, we studied the effect of Oersted magnetic fields on the chirality of transverse magnetic domain walls in Fe$_{20}$Ni$_{80}$/Ir bilayer nanostrips. Applying nanosecond current pulses with a current density of around $2\times10^{12}$ A/m$^2$, the chirality of a transverse domain wall could be switched reversibly and reproducibly. These current densities are similar to the ones used for current-induced domain wall motion, indicating that the Oersted field may stabilize the transverse wall chirality during current pulses and prevent domain wall transformations.