Keatley, P. and Aziz, Atif and Ali, M. and Kickey, B. J. and Blamire, M. G. and Kicken, R. J. (2014) Optical characterization of non-local spin transfer torque acting on a single nanomagnet. Physical review B, 89 (9): 094421. ISSN 1098-0121
Abstract
Time-resolved scanning Kerr microscopy (TRSKM) has been used to examine the effect of nonlocal spin transfer torque (NL-STT) within a two-terminal current perpendicular-to-plane nonlocal spin valve. A combination of Oersted field and NL-STT was used to excite and control the magnetization dynamics. By comparison with a macrospin model, the strength of the NL-STT was quantified and found to be comparable to that achieved by direct injection of spin-polarized current. The sensitivity of the magneto-optical probe to small out-of-plane deflections of the magnetization also allows the NL-STT to be quantified in quasi-dc measurements, greatly simplifying the investigation of STT phenomena.