title: Electron-electron interaction in the magnetoresistance of graphene.
abstract: We investigate the magnetotransport in large area graphene Hall bars epitaxially grown on silicon carbide. In the intermediate field regime between weak localization and Landau quantization, the observed temperature-dependent parabolic magnetoresistivity is a manifestation of the electron-electron interaction. We can consistently describe the data with a model for diffusive (magneto)transport that also includes magnetic-field-dependent effects originating from ballistic time scales. We find an excellent agreement between the experimentally observed temperature dependence of magnetoresistivity and the theory of electron-electron interaction in the diffusive regime. We can further assign a temperature-driven crossover to the reduction of the multiplet modes contributing to electron-electron interaction from 7 to 3 due to intervalley scattering. In addition, we find a temperature-independent ballistic contribution to the magnetoresistivity in classically strong magnetic fields.
authors.affiliation: Lehrstuhl für Angewandte Physik, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Jobst
authors.forename: Daniel
authors.initials: D
authors.lastname: Waldmann
authors.forename: Igor V
authors.initials: IV
authors.lastname: Gornyi
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Mirlin
authors.forename: Heiko B
authors.initials: HB
authors.lastname: Weber