Giant quantum Hall plateaus generated by charge transfer in epitaxial graphene
2016 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, no 30296Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
Nature Publishing Group, 2016. Vol. 6, no 30296
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-130834DOI: 10.1038/srep30296ISI: 000380203800001PubMedID: 27456765OAI: oai:DiVA.org:liu-130834DiVA: diva2:955823
Funding Agencies|UK EPSRC; Graphene Flagship [CNECT-ICT-604391]; EMRP project GraphOhm; AFRL grant [FA9550-15-C-0067]; LNCMI-CNRS; International Collaborative Energy Technology R&D Program of the Korean Institute of Energy Technology Evaluation and Planning (KETEP); Ministry of Trade, Industry & Energy, Republic of Korea 2016-08-262016-08-262016-09-15Bibliographically approved