Perfect alloys for spin Hall current induced magnetization switching

We propose a device that allows for magnetization switching in nanomagnets by means of a pure spin current induced by the spin Hall effect. For this purpose we combine the ideas of magnetization switching of a ferromagnet by a spin current caused by the spin accumulation at a ferromagnet/nonmagnet interface with the electronic measurement of the direct spin Hall effect, and the theoretical material design to identify systems with a large spin Hall angle and an appropriate spin diffusion length. We will discuss the device design with respect to the size of the charge and spin currents. Based on ab initio calculations, we predict dilute alloys ideally suited for this application. Noble metals with single-sheeted Fermi surfaces doped with either heavy impurities like Bi and Pb in Cu or Bi in Ag and light impurities like C and N in Au seem to be the best candidates for a spin Hall angle larger than 5%.