Speaker
John Q Xiao
(University of Delaware)
Description
Spin-orbital coupling driven toques have been observed in magnetic bilayers consisting of a ferromagnet (FM) and heavy metal (HM) or topological insulator (TI). It has been demonstrated that the spin-orbit torques driven by an in-plane current can switch magnetization, manipulate magnetic domains and excite magnetization auto-oscillation. However, the microscopic mechanism for the spin-orbit torques is still under debate. One of the questions is how to differential the contributions from interface due to the Rashba effect or from bulk of nonmagnetic layer due to the spin Hall effect. In this talk, we will present a newly developed, magneto-optic-Kerr-effect (MOKE) based spin-orbit torque magnetometer that measures both field-like torque (TSOF) and damping-like torque (TSOT) with various thicknesses of the FM, HM TL layers. The technique also offers both spatial and time resolution. We observed both TSOF and TSOT are nonlocal and does not require direct contact between FM and HM. By engineering the interface which modifies the Rashba interaction, we are able to show the co-existence of spin Hall and Rashba effect as well as quantify both contributions to spin-orbit torques.
Author
John Q Xiao
(University of Delaware)
Co-authors
Mrs
Halise Celik
(University of Delaware)
Mr
Jun Wu
(University of Delaware)
Prof.
Kyung-Jin Lee
(Korea University)
Prof.
Virginia O. Lorenz
(University of Delaware)
Mr
Wenrui Wang
(University of Delaware)
Prof.
Xin Fan
(University of Denver)
Mr
yunpeng Chen
(University of Delaware)
