Current-induced domain wall motion along high perpendicular magnetocrystalline anisotropy multilayers is studied by means of full micromagnetic simulations and a one-dimensional model in the presence of in-plane fields. We consider domain wall motion driven by the spin Hall effect in the presence of the Dzyaloshinskii-Moriya interaction (DMI). In the case of relatively weak DMI, the wall propagates without significant tilting of the wall plane, and the full micromagnetic results are quantitatively reproduced by a simple rigid one-dimensional model. By contrast, significant wall-plane tilting is observed in the case of strong DMI, and a one-dimensional description including the wall tilting is required to qualitatively describe the micromagnetic results. However, in this strong-DMI case, the one-dimensional model exhibits significant quantitative discrepancies from the full micromagnetic results, in particular, when high longitudinal fields are applied in the direction of the internal domain wall magnetization. It is also shown that, even under thermal fluctuations and edge roughness, the domain wall develops a net tilting angle during its current-induced motion along samples with strong DMI. V

We study the effect of the Dzyaloshinskii-Moriya interaction (DMI) on current-induced magnetic switching of a perpendicularly magnetized heavy-metal/ferromagnet/oxide trilayer both experimentally and through micromagnetic simulations. We report the generation of stable helical magnetization stripes for a sufficiently large DMI strength in the switching region, giving rise to intermediate states in the magnetization confirming the essential role of the DMI on switching processes. We compare the simulation and experimental results to a macrospin model, showing the need for a micromagnetic approach. The influence of the temperature on the switching is also discussed.

Spin orbit interactions are rapidly emerging as the key for enabling efficient current-controlled spintronic devices. Much work has focused on the role of spin-orbit coupling at heavy metal/ferromagnet interfaces in generating current-induced spin-orbit torques. However, the strong influence of the spin-orbit-derived Dzyaloshinskii-Moriya interaction (DMI) on spin textures in these materials is now becoming apparent. Recent reports suggest DMI-stabilized homochiral domain walls (DWs) can be driven with high efficiency by spin torque from the spin Hall effect. However, the influence of the DMI on the current-induced magnetization switching has not been explored nor is yet well-understood, due in part to the difficulty of disentangling spin torques and spin textures in nano-sized confined samples. Here we study the magnetization reversal of perpendicular magnetized ultrathin dots, and show that the switching mechanism is strongly influenced by the DMI, which promotes a universal chiral non-uniform reversal, even for small samples at the nanoscale. We show that ultrafast current-induced and field-induced magnetization switching consists on local magnetization reversal with domain wall nucleation followed by its propagation along the sample. These findings, not seen in conventional materials, provide essential insights for understanding and exploiting chiral magnetism for emerging spintronics applications.

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Spin waves can transport both energy and angular momentum over long distances as they propagate. However, due to damping, their amplitude decreases exponentially as they move away from the source, leaving little capability for manipulating how much energy and angular momentum is to be delivered where. Here we show that a suitable local reduction of the effective field can lead to a large accumulation of spin wave energy far from the source. Moreover, both the location and the amount of energy to be delivered can be controlled accurately with geometry and external magnetic fields. Thus, we put forward a general, robust and flexible approach to convey both heat and spin in ferromagnets, which can be directly used in spintronic devices. * noelpg@usal.es 1 arXiv:1412.4129v1 [cond-mat.mes-hall]