title: Giant quantum Hall plateaus generated by charge transfer in epitaxial graphene.
abstract: Epitaxial graphene has proven itself to be the best candidate for quantum electrical resistance standards due to its wide quantum Hall plateaus with exceptionally high breakdown currents. However one key underlying mechanism, a magnetic field dependent charge transfer process, is yet to be fully understood. Here we report measurements of the quantum Hall effect in epitaxial graphene showing the widest quantum Hall plateau observed to date extending over 50 T, attributed to an almost linear increase in carrier density with magnetic field. This behaviour is strong evidence for field dependent charge transfer from charge reservoirs with exceptionally high densities of states in close proximity to the graphene. Using a realistic framework of broadened Landau levels we model the densities of donor states and predict the field dependence of charge transfer in excellent agreement with experimental results, thus providing a guide towards engineering epitaxial graphene for applications such as quantum metrology.
authors.affiliation: Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom.
authors.forename: J A
authors.initials: JA
authors.lastname: Alexander-Webber
authors.affiliation: Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Huang
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143, avenue de Rangueil, 31400 Toulouse, France.
authors.forename: D K
authors.initials: DK
authors.lastname: Maude
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom.
authors.forename: T J B M
authors.initials: TJ
authors.lastname: Janssen
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom.|Department of Physics, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Tzalenchuk
authors.affiliation: Department of Physics, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom.
authors.forename: V
authors.initials: V
authors.lastname: Antonov
authors.affiliation: Department of Microtechnology and Nanoscience, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Yager
authors.affiliation: Department of Microtechnology and Nanoscience, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Lara-Avila
authors.affiliation: Department of Microtechnology and Nanoscience, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Kubatkin
authors.affiliation: Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83 Linköping, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Yakimova
authors.affiliation: Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom.
authors.forename: R J
authors.initials: RJ
authors.lastname: Nicholas