Quantum corrections to the conductivity of disordered graphene on SiC Weak localization and current-bias dependent electron-electron interactions

Abstract

The properties of epitaxial graphene grown via thermal decomposition of silicon carbide are extremely sensitive to annealing conditions. Here we show how the surface morphologies resulting from a range of UHV growth protocols affect the electron scattering rates associated with various quantum corrections to the conductivity. Detailed analysis of magnetotransport data provides insight into the degree of disorder via fits to weak localization and weak antilocalization models, while additional fitting is used to identify more subtle contributions from electron-electron (e-e) interaction effects. This second contribution is found to be current-bias dependent, and is seen only for more disordered samples, which is attributed to the shorter mean free path in these materials. © 2014 IOP Publishing and Deutsche Physikalische Gesellschaft.