Giant quantum Hall plateaus generated by charge transfer in epitaxial graphene
Journal article, 2016
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.
Electronic properties and devices
graphene
Quantum Hall
Author
J. A. Alexander-Webber
University of Oxford
University of Cambridge
J. Huang
University of Oxford
D. K. Maude
Centre national de la recherche scientifique (CNRS)
Tjbm Janssen
National Physical Laboratory (NPL)
A.Y. Tzalenchuk
National Physical Laboratory (NPL)
Royal Holloway University of London
V. Antonov
Royal Holloway University of London
Thomas Yager
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Samuel Lara Avila
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Sergey Kubatkin
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
R. Yakimova
Linköping University
R. J. Nicholas
University of Oxford
Scientific Reports
2045-2322 (ISSN) 20452322 (eISSN)
Vol. 6 30296Subject Categories
Nano Technology
Condensed Matter Physics
Areas of Advance
Materials Science
DOI
10.1038/srep30296