Tunable multistate field-free switching and ratchet effect by spin-orbit torque in canted ferrimagnetic alloy

Cheng-Hsiang Hsu; Miela J Gross; Hannah Calzi Kleidermacher; Shehrin Sayed; Sayeef Salahuddin

doi:10.1038/s41467-024-52834-0

Tunable multistate field-free switching and ratchet effect by spin-orbit torque in canted ferrimagnetic alloy

Nat Commun. 2024 Oct 8;15(1):8713. doi: 10.1038/s41467-024-52834-0.

Authors

Cheng-Hsiang Hsu^{1

2}, Miela J Gross³, Hannah Calzi Kleidermacher⁴, Shehrin Sayed^{4

5}, Sayeef Salahuddin^{6

7}

Affiliations

¹ Department of Electrical Engineering and Computer Science, University of California, Berkeley, California, USA. [email protected].
² Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA. [email protected].
³ Department of Physics, University of California, Berkeley, California, USA.
⁴ Department of Electrical Engineering and Computer Science, University of California, Berkeley, California, USA.
⁵ Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.
⁶ Department of Electrical Engineering and Computer Science, University of California, Berkeley, California, USA. [email protected].
⁷ Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA. [email protected].

Abstract

Spin-orbit torque is not only a useful probe to study manipulation of magnetic textures and magnetic states at the nanoscale but also it carries great potential for next-generation computing applications. Here we report the observation of rich spin-orbit torque switching phenomena such as field-free switching, multistate switching, memristor behavior and ratchet effect in a single shot, co-sputtered, rare earth-transition metal Gd_xCo_100-x. Notably such effects have only been observed in antiferromagnet/ferromagnet bi-layer systems previously. We show that these effects can be traced to a large anistropic canting, that can be engineered into the Gd_xCo_100-x system. Further, we show that the magnitude of these switching phenomena can be tuned by the canting angle and the in-plane external field. The complex spin-orbit torque switching observed in canted Gd_xCo_100-x not only provides a platform for spintronics but also serves as a model system to study the underlying physics of complex magnetic textures and interactions.