Observation of spin-orbit effects with spin rotation symmetry
Alisha Humphries, Tao Wang, Eric R. Edwards, Shane Allen, Justin M. Shaw, Hans T. Nembach, John Xiao, Thomas J. Silva
The spin-orbit interaction in a nonmagnetic/magnetic multilayer has been intensively studied due to its efficient conversion between a spin current and a charge current. In the spin Hall/Rashba-Edelstein effects (SHE/REE) and inverse spin Hall/Rashba-Edelstein effects (ISHE/IREE), the charge current, spin current and spin directions are orthogonal to each other in the nonmagnetic material. Here we report the generation of the spin-orbit torque (SOT) and ISHE/IREE voltage in unconventional directions by replacing the nonmagnetic material with a magnetic metal. In a spin valve-like multilayer with orthogonal magnetization configurations, we observe SOTs on the in-plane magnetized layer in the direction that is rotated 90� from the conventional SOTs around the out-of-plane magnetization of the other magnetic layer. We further measure the ISHE/IREE generated by an out-of-plane temperature gradient in the same sample and observe the ISHE/IREE voltage with a similar rotated symmetry. These findings present interesting spin-orbit effects in magnetic multilayers and may have potential impact in the application of magnetic random-access memories.