%0 Journal Article
%T Switching of perpendicular magnetization by spin-orbit torques in the absence of external magnetic fields
%A Guoqiang Yu
%A Pramey Upadhyaya
%A Yabin Fan
%A Juan G Alzate
%A Wanjun Jiang
%A Kin L. Wong
%A So Takei
%A Scott A Bender
%A Murong Lang
%A Jianshi Tang
%A Yaroslav Tserkovnyak
%A Pedram Khalili Amiri
%A Kang L. Wang
%J Physics
%D 2013
%I arXiv
%R 10.1038/nnano.2014.94
%X Magnetization switching by current-induced spin-orbit torques (SOTs) is of great interest due to its potential applications for ultralow-power memory and logic devices. In order to be of technological interest, SOT effects need to switch ferromagnets with a perpendicular (out-of-plane) magnetization. Currently, however, this typically requires the presence of an in-plane external magnetic field, which is a major obstacle for practical applications. Here we report for the first time on SOT-induced switching of out-of-plane magnetized Ta/Co20Fe60B20/TaOx structures without the need for any external magnetic fields, driven by in-plane currents. This is achieved by introducing a lateral structural asymmetry into our devices during fabrication. The results show that a new field-like SOT is induced by in-plane currents in such asymmetric structures. The direction of the current-induced effective field corresponding to this new field-like SOT is out-of-plane, which facilitates switching of perpendicular magnets. This work thus provides a pathway towards bias-field-free SOT devices.
%U http://arxiv.org/abs/1311.0929v1