Remarkably enhanced current-driven 360° domain wall motion in nanostripe by tuning in-plane biaxial anisotropy

Abstract

By micromagnetic simulations, we study the current-driven 360° domain wall (360DW) motion in ferromagnetic nanostripe with an in-plane biaxial anisotropy. We observe the critical annihilation current of 360° domain wall can be enhanced through such a type of anisotropy, the reason of which is the suppression of out-of-plane magnetic moments generated simultaneously with domain-wall motion. In details, We have found that the domain-wall width is only related to K y − K x, with K x(y) the anisotropy constant in x(y) direction. Taking domain-wall width into consideration, a prior choice is to keep K y ≈ K x with large enough K. The mode of domain-wall motion has been investigated as well. The traveling-wave-motion region increases with K, while the average DW velocity is almost unchanged. Another noteworthy feature is that a Walker-breakdown-like motion exists before annihilation. In this region, though domain wall moves with an oscillating behavior, the average velocity does not reduce dramatically, but even rise again for a large K.

Survey of 360$^{\circ}$ domain walls in magnetic heterostructures: topology, chirality and current-driven dynamics

“…Interestingly, both modes share the same wall mobility which is equal to that in steady-flow mode of 180DWs. This explains nearly all existing numerical observations before 360DWs change to other magnetic solitons (for example vortices) under too high currents [55,60,61].…”

“…Accordingly, strong enough external stimuli would destroy the configuration of 360DWs, thereby greatly change the mobility of domain walls (not 360DWs any more). This explains the huge reduction of 360DW mobility under high currents in existing numerics [55,60,61].…”

“…Indeed, it is the most common way to implement and manipulate in real MHs. Numerical investigations on this issue have been widely preformed in the past decade [55][56][57][58][59][60][61]. Alternatively, there are few analytical studies due to the complexity from the coexistence of iDMI, spin-transfer torque (STT) and spin-orbit torque (SOT) therein.…”

Current driven properties and the associated magnetic domain walls manipulation in U-shaped magnetic nanowires

“…In recent years, many experiments have observed the phenomenon of current driven magnetic domain wall motion in magnetic nanostructures [1][2][3][4][5][6][7], and there have also been many theoretical works to reveal the physical mechanisms of the related experimental phenomena [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. However, most of the research is limited to the movement properties of current driven the single magnetic domain walls in long straight magnetic nanowires.…”

Walker solution for Dzyaloshinskii domain wall in ultrathin ferromagnetic films

“…Moreover, in the absence of DMI we find an entire family of exact solutions for every angle between the DW normal and the in-plane easy axis. Although the dynamics in biaxial ferromagnets has been the subject of many works (see, e.g., [32][33][34][35][36]), the interplay between DMI and biaxial anisotropy leads to additional interesting phenomena.…”