  We report the first demonstration of the current-induced magnetization
switching in a perpendicularly magnetized A1 CoPt single layer. We show that
good perpendicular magnetic anisotropy can be obtained in a wide composition
range of the A1 Co1-xPtx single layers, which allows to fabricate
perpendicularly magnetized CoPt single layer with composition gradient to break
the inversion symmetry of the structure. By fabricating the gradient CoPt
single layer, we have evaluated the SOT efficiency and successfully realized
the SOT-induced magnetization switching. Our study provides an approach to
realize the current-induced magnetization in the ferromagnetic single layers
without attaching SOT source materials.
