Giant quantum Hall plateaus generated by charge transfer in epitaxial graphene
Artikel i vetenskaplig tidskrift, 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.

graphene

Quantum Hall

Electronic properties and devices

Författare

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

Royal Holloway University of London

National Physical Laboratory (NPL)

V. Antonov

Royal Holloway University of London

Thomas Yager

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Samuel Lara Avila

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Sergey Kubatkin

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

R. Yakimova

Linköpings universitet

R. J. Nicholas

University of Oxford

Scientific Reports

2045-2322 (ISSN)

Vol. 6 30296

Ämneskategorier

Nanoteknik

Styrkeområden

Materialvetenskap

DOI

10.1038/srep30296