Tuning the spintronic properties of graphene with atomically precise Au clusters

Abstract

Spin relaxation is investigated in lateral nonlocal graphene spin valves with increasing densities of soft-landed Au-3 and Au-6 clusters. It is found that both gold clusters scatter spins via the Elliot-Yafet mechanism. The induced spin-orbit coupling strength is a few meV for both clusters, with the value for Au-3 being roughly twice as large as that of Au-6. A gradual increase of the deposited cluster density (up to similar to 10(14) clusters cm(-2)) decreases the spin and momentum lifetime of the graphene channel, with Au-6 clusters affecting both spin and momentum lifetime more strongly than the Au-3 clusters. Density functional theory calculations provide insights into the spin relaxation mechanism. The dependence of graphene's electronic and spintronic properties on the density and the exact cluster size indicates the importance of the microscopic details for graphene functionalisation towards spintronic applications.