Paper

Field-free switching of perpendicular magnetization in an ultrathin epitaxial magnetic insulator

George, Jean-Marie, Prestes, Nicholas F, Denneulin, Thibaud, Thiaville, André, Collin, Sophie, Fayet, Olivier, Bibes, Manuel, Jacquet, Eric, Fert, Albert, Reyren, Nicolas, Godel, Florian, Jaffrès, Henri, Husain, Sajid, Dunin-Borkowski, Rafal E

2023

Overview

For energy efficient and fast magnetic memories, switching of perpendicular magnetization by the spin-orbit torque (SOT) appears as a very promising solution, even more using magnetic insulators that suppress electrical shunting. This SOT switching generally requires the assistance of an in-plane magnetic field to break the symmetry. Here, we present experiments demonstrating the field-free SOT switching of perpendicularly magnetized layers of the thulium iron garnet (Tm_{3}Fe_{5}O_{12}) magnetic insulator. The polarity of the switching loops, clockwise (CW) or counter-clockwise (CCW), is determined by the direction of the initial current pulses, in contrast with field-assisted switchings in which this polarity is controlled by the direction of the field. After an independent determination of Dzyaloshinskii-Moriya interaction (DMI), we relate the field free switching to the interplay of SOT and DMI and the polarity of the loops to the imprint of a Néel domain wall induced by the first pulse, in agreement with Kerr imaging. Our observation and interpretation of field-free electrical switching of a magnetic insulator is an important milestone for future low power spintronic devices.

• Publisher: Cornell University Library, arXiv.org
• Subject: Current pulses / Domain walls / Insulators / Iron / Magnetization / Switching / Thulium