Experimental and Theoretical Evaluation for Pressure Effects on Spin Hall Effect in Pt

We have experimentally evaluated the influence of pressure on the spin Hall effect for the Pt by using a laterally configured Pt/CoFeB hybrid nanostructure. Experimental results suggest that the spin Hall angle for the Pt is almost constant under the pressure up to 2 GPa. We have also developed the theoretical evaluation method for the pressure dependence of the spin Hall angle by using the first-principles calculation. The theoretical results also show the spin Hall angle for the Pt is insensitive to the pressure up to 75 GPa. These results imply that the enhanced spin Hall signal in the dynamical spin injection due to the pressure application is caused by the modification of the spin mixing conductance at the Pt/CoFeB interface.