title: Magneto-optical investigation of spin-orbit torques in metallic and insulating magnetic heterostructures.
abstract: Manipulating magnetism by electric current is of great interest for both fundamental and technological reasons. Much effort has been dedicated to spin-orbit torques (SOTs) in metallic structures, while quantitative investigation of analogous phenomena in magnetic insulators remains challenging due to their low electrical conductivity. Here we address this challenge by exploiting the interaction of light with magnetic order, to directly measure SOTs in both metallic and insulating structures. The equivalency of optical and transport measurements is established by investigating a heavy-metal/ferromagnetic-metal device (Ta/CoFeB/MgO). Subsequently, SOTs are measured optically in the contrasting case of a magnetic-insulator/heavy-metal (YIG/Pt) heterostructure, where analogous transport measurements are not viable. We observe a large anti-damping torque in the YIG/Pt system, revealing its promise for spintronic device applications. Moreover, our results demonstrate that SOT physics is directly accessible by optical means in a range of materials, where transport measurements may not be possible.
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Montazeri
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Pramey
authors.initials: P
authors.lastname: Upadhyaya
authors.affiliation: Departmentof Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Mehmet C
authors.initials: MC
authors.lastname: Onbasli
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yu
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Kin L
authors.initials: KL
authors.lastname: Wong
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Murong
authors.initials: M
authors.lastname: Lang
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Yabin
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Pedram
authors.initials: P
authors.lastname: Khalili Amiri
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Schwartz
authors.affiliation: Departmentof Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Ross
authors.affiliation: Department of Electrical Engineering, Device Research Laboratory, University of California, Los Angeles, California 90095, USA.
authors.forename: Kang L
authors.initials: KL
authors.lastname: Wang