Highly Asymmetric Chiral Domain-Wall Velocities in Y-Shaped Junctions

Abstract

Recent developments in spin-orbit torques allow for highly efficient current-driven domain wall (DW) motion in nanowires with perpendicular magnetic anisotropy. Here, we show that chiral DWs can be driven into nonequilibrium states that can persist over tens of nanoseconds in Y-shaped magnetic nanowire junctions that have an input and two symmetric outputs. A single DW that is injected into the input splits and travels at very different velocities in the two output branches until it reaches its steady-state velocity. We find that this is due to the disparity between the fast temporal evolution of the spin current derived spin-orbit torque and a much-slower temporal evolution of the DMI-derived torque. Changing the DW polarity inverts the velocity asymmetry in the two output branches, a property that we use to demonstrate the sorting of domains.

Advances in artificial spin ice

“…2i,j). Taking advantage of this asymmetry, a domain wall passing through tailored Y-junctions, which are the basic units of connected artificial kagome spin ice, can be used to perform logic operations 62,63 . However, care is needed because the walls may transform into domain walls of opposite chirality for particular magnetic fields and geometries 64,65 , and the propagation behaviour of the domain walls depends on the magnitude and orientation of the applied magnetic fields [66][67][68] .…”

Ionitronic manipulation of current-induced domain wall motion in synthetic antiferromagnets

“…It has previously been shown that DWs in a perfectly compensated SAF structure can move freely regardless of the track geometry, e.g. the curvature of the wires, by current, whereas in FM structures, the DW motion is strongly affected by local geometries and the DW con guration (up/down or down/up) 26,27 . From this example of a "knot" device, we illustrate that by taking advantage of the large ILG induced effects on CIDWM in SAF structures, these effects have potential for novel logic devices using suitably designed racetrack device geometries.…”

Current-induced dynamical tilting of chiral domain walls in curved microwires

“…Here, the duration and polarity of the CIDWM pulse could be employed to define the logic operation, providing an additional arrow in the quiver for DW-based devices, in principle extending the range of operations beyond the results already reported for straight microwires in Ref. [13].…”

“…Here, multiple works have demonstrated the feasibility of the racetrack memory design both quasi-statically [7][8][9] and dynamically [10,11]. Furthermore, various geometrical designs of the racetrack enable different operations on the DWs, including DW logic [12], and DW sorting [13], providing an avenue towards applications such as DW computing.…”