Room-Temperature Current-Induced Generation and Motion of sub-100 nm Skyrmions

William Legrand (1) , Davide Maccariello (1) , Nicolas Reyren (1) , Karin Garcia (1) , Christoforos Moutafis (2) , Constance Moreau-Luchaire (1) , Sophie Collin (1) , Karim Bouzehouane (1) , Vincent Cros (1) , Albert Fert (1)

1 Laboratoire Albert Fert (ex-UMPhy Unité mixte de physique CNRS/Thales)
2 CAM - University of Cambridge [UK]

Magnetic skyrmions are nanoscale windings of the spin configuration that hold great promise for technology due to their topology-related properties and extremely reduced sizes. After the recent observation at room temperature of sub-100 nm skyrmions stabilized by interfacial chiral interaction in magnetic multilayers, several pending questions remain to be solved, notably about the means to nucleate individual compact skyrmions or the exact nature of their motion. In this study, a method leading to the formation of magnetic skyrmions in a micrometer-sized track using homogeneous current injection is evidenced. Spin-transfer-induced motion of these small electrical-current-generated skyrmions is then demonstrated and the role of the out-of-plane magnetic field in the stabilization of the moving skyrmions is also analyzed. The results of these experimental observations of spin torque induced motion are compared to micromagnetic simulations reproducing a granular type, nonuniform magnetic multilayer in order to address the particularly important role of the magnetic inhomogeneities on the current-induced motion of sub-100 nm skyrmions for which the material grains size is comparable to the skyrmion diameter.

Mots clés: micromagnetics; Skyrmion; spin−orbit torque; room-temperature imaging; magnetic multilayers; current−induced motion

Domaines: Matière Condensée [cond-mat]

William Legrand, Davide Maccariello, Nicolas Reyren, Karin Garcia, Christoforos Moutafis, et al.. Room-Temperature Current-Induced Generation and Motion of sub-100 nm Skyrmions. Nano Letters, 2017, 17 (4), pp.2703-2712. ⟨10.1021/acs.nanolett.7b00649⟩. ⟨hal-02076552⟩