Regensburg 2019 – wissenschaftliches Programm
MA 38.3: Vortrag
Mittwoch, 3. April 2019, 17:45–18:00, H52
High-speed domain-wall motion driven by spin-orbit torques and Dzyaloshinskii-Moriya interaction in a magnetic insulator — •Saül Vélez1,2, Jakob Schaab1,2, Marvin Müller1, Elzbieta Gradauskaite1, Morgan Trassin1, Manfred Fiebig1, and Pietro Gambardella1 — 1ETH Zürich — 2Equally contributing
Electrical manipulation of magnetic domains and domain walls (DWs) in magnetic films is an essential ingredient for the development of novel functional devices. Current-induced spin-orbit torques (SOTs) can deterministically switch thin magnetic films and drive Néel chiral DWs at high speeds. The recent addition of magnetic insulators (MIs) as SOT-switchable magnetic layers have prospects for the development of novel non-volatile magnonic logic circuits and memories. However, key aspects such as the dynamics of DWs induced by SOTs in MIs remain so far unexplored. Here, by implementing magneto-optical Kerr effect microscopy, we demonstrate efficient SOT-manipulation of chiral DWs in Tm3Fe5O12(TmIG)/Pt -stabilized by a small in-plane field-, with measured velocities of up to 400 m/s at current densities ∼1.5×108 A/cm2. The high quality of the TmIG crystals leads to a very low current subthreshold for DW flow ∼5×106 A/cm2, extremely small depinning fields (∼1-2 Oe) and to extraordinarily large DW displacements upon domain contraction. We also identify Dzyaloshinskii-Moriya interaction (DMI) in TmIG/Pt, with slightly favored left-handed Néel chiral DWs. All these findings point MIs as strong candidates to compete with metallic ferromagnets for spintronic applications, yet enabling the implementation of complementary functionalities.