Transport in adatom-decorated graphene

The 2D electronic system in graphene and other atomically-thin materials is unprotected from the environment and so can be readily disordered by numerous extrinsic sources. While often a nuisance, this fact may also be used to advantage if, for instance, the electronic structure can be controllably altered in useful or interesting ways. In particular, several theoretical works have predicted that a strong spin-orbit coupling can be induced in graphene by proximity to certain transition metal atoms, either as surface adatoms or as a component of the supporting substrate. Ultimately one may hope to realize the Kane-Mele 2D topological insulator composed of graphene with a spin-orbit coupling. Here we report progress toward this goal through experiments on devices containing graphene decorated with osmium or tungsten adatoms, where these metals are deposited in situ and followed by measurements of the electronic transport.