Threshold current for switching of a perpendicular magnetic layer induced by spin Hall effect

We theoretically investigate the switching of a perpendicular magnetic layer by in-plane charge current due to the spin Hall effect. We find that in the high damping regime, the threshold switching current is independent of the damping constant and is almost linearly proportional to both effective perpendicular magnetic anisotropy field and external in-plane field applied along the current direction. We obtain an analytic expression of the threshold current, in excellent agreement with numerical results. Based on the expression, we find that magnetization switching induced by the spin Hall effect can be practically useful when it is combined with voltage-controlled anisotropy change. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4798288]