Enhancement of the spin pumping efficiency by spin wave mode selection

The spin pumping efficiency of standing spin wave modes in a rectangular Y3Fe5O12/Pt sample has been investigated by means of inverse spin-Hall effect (ISHE). Standing spin waves drive spin pumping, the generation of spin currents from magnetization precession, into the Pt layer which is converted into a detectable voltage due to the ISHE. We discovered that the spin pumping efficiency is significantly higher for standing surface spin waves, hybridized with thickness modes, rather than for volume spin wave modes. The results suggest that the use of higher-mode surface spin waves allows for the fabrication of an efficient spin-current injector.