All-optical vector measurement of spin-orbit-induced torques using both polar and quadratic magneto-optic Kerr effects

作者：Fan Xin^*; Mellnik Alex R; Wang Wenrui; Reynolds Neal; Wang Tao; Celik Halise; Lorenz Virginia O; Ralph Daniel C; Xiao John Q

来源：Applied Physics Letters, 2016, 109(12): 122406.

DOI：10.1063/1.4962402

We demonstrate that the magneto-optic-Kerr effect with normal light incidence can be used to obtain quantitative optical measurements of both components of spin-orbit-induced torque ( both the antidamping and effective-field components) in heavy-metal/ferromagnet bilayers. This is achieved by analyzing the quadratic Kerr effect as well as the polar Kerr effect. The two effects can be distinguished by properly selecting the polarization of the incident light. We use this all-optical technique to determine the spin-orbit torques generated by a series of Pt/Permalloy samples, finding values in excellent agreement with spin-torque ferromagnetic resonance measurements. Published by AIP Publishing.

• 出版日期2016-9-19