Work

Unconventional angular dependence of spin-orbit torque-induced harmonic Hall resistance in Pt/YIG bilayers

Year: 2024

Type: article

Abstract: Spin-orbit torque (SOT), arising from spin-orbit coupling-induced spin currents, provides efficient control of magnetization. SOT characterization involving harmonic Hall resistances is typically done in low-current regimes, distinct from high-current regimes, where SOT-induced magnetization switching occurs. In this study, we investigate azimuthal angle ( ϕ )-dependent harmonic Hall resistances of a Pt/yttrium iron garnet (YIG) layer across a wide range of measurement currents. Under low-current conditions, conventional ϕ -dependent Hall resistances are observed; the first harmonic Hall resistance exhibits sin 2 ϕ behavior and the second harmonic Hall resistance comprises cos ϕ and cos 3 ϕ terms. Interestingly, with increasing current, higher-order angular-dependent terms become non-negligible, referring to the sin 4 ϕ and sin 6 ϕ terms for the first harmonic and the cos 5 ϕ and cos 7 ϕ terms for the second harmonic Hall resistances. We attribute this unconventional angular dependence to the nonlinear response of magnetization direction to SOT, emphasizing its relevance to understanding the magnetization dynamics during SOT-induced switching under large currents.

Source: npj Spintronics

DOI: 10.1038/s44306-024-00050-3

Authors: Takayuki Shiino, Phuoc Cao Van, Jong-Guk Choi, Geunwoo Kim, Jong-Ryul Jeong, Byong-Guk Park

Institutions: Korea Advanced Institute of Science and Technology, Chungnam National University

Language: English

Topic: Magnetic properties of thin films

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,090

Funders: National Research Foundation, National Research Foundation of Korea