Scanning tunneling microscopy and electronic transport of gold-decorated graphene devices*

Past studies on graphene show that scattering from disorder can give rise to weak Anderson localization, but a disorder-driven quantum metal-insulator transition has not been observed. Using a low temperature scanning tunneling microscope (STM) on graphene field effect transistors, we present simultaneous STM and electronic transport measurements of graphene devices decorated with gold adatoms. These data show quasiparticle scattering off of gold adatoms on graphene on SiO2/Si. We study the microscopic scattering mechanisms, including the effects of charge puddles versus point-like disorder, and correlate these mechanisms with macroscopic electronic transport. These experiments are the first steps toward understanding the phase space near disorder-tuned metal-insulator quantum phase transitions in 2D materials.