Dispersive Stiffness of Dzyaloshinskii Domain Walls

Abstract

It is well documented that subjecting perpendicular magnetic films that exhibit the interfacial Dzyaloshinskii-Moriya interaction to an in-plane magnetic field results in a domain wall (DW) energy σ, which is highly anisotropic with respect to the orientation of the DW in the film plane Θ. We demonstrate that this anisotropy has a profound impact on the elastic response of the DW as characterized by the surface stiffness σ[over ˜](Θ)=σ(Θ)+σ^{''}(Θ) and evaluate its dependence on the length scale of deformation. The influence of stiffness on DW mobility in the creep regime is assessed, with analytic and numerical calculations showing trends in σ[over ˜] that better represent experimental measurements of domain wall velocity in magnetic thin films compared to σ alone. Our treatment provides experimental support for theoretical models of the mobility of anisotropic elastic manifolds and makes progress toward a more complete understanding of magnetic domain wall creep.

Domain-wall motion and interfacial Dzyaloshinskii-Moriya interactions inPt/Co/Ir(tIr)/Tamultilayers

“…Whilst none of these features can be explained with the theory of asymmetric bubble expansion in Ref. 16, some have also been seen in other experiments on different structures 26,27,31 . This suggests that the approach used in Eq.…”

Magnetic domain wall skyrmions

“…Similar to constriction of the DW profile in a VBL due to the increased demagnetization energy [26], the presence of a DW-Skyrmion also locally deforms the DW profile due to DMI. Because the internal magnetization is inevitably tilted away from the DW normal in a DW Skyrmion, there is a driving force for the DW itself to bend locally as an attempt to recover this energy; this phenomenon is similar to the spontaneous tilting of Dzyaloshinskii DWs identified in [7,27]. To capture this effect, we adopt a modified Slonczewski ansatz for the profile function that involves two independent variables…”

Lorentz TEM investigation of chiral spin textures and Néel Skyrmions in asymmetric [Pt/(Co/Ni)M/Ir]N multi-layer thin films

“…Such objects are stabilized by the Dzyaloshinskii-Moriya interaction (DMI) which is found in magnetic materials where inversion symmetry is broken [4,5]. This interaction has been observed in bulk magnetic materials lacking inversion symmetry (such as FeGe [6] and MnSi [7]) and more recently in magnetic multi-layers at the interface of a ferromagnet (FM) and a heavy metal (HM) with large spin-orbit coupling [8][9][10]. In the latter case, interfacial DMI is well-established to stabilize chiral Néel DWs over the magnetostatically favorable Bloch wall [11].…”