Polymer-encapsulated molecular doped epigraphene for quantum resistance metrology
Journal article, 2019
One of the aspirations of quantum metrology is to deliver primary standards directly to end-users thereby significantly shortening the traceability chains and enabling more accurate products. Epitaxial graphene grown on silicon carbide (epigraphene) is known to be a viable candidate for a primary realisation of a quantum Hall resistance standard, surpassing conventional semiconductor two-dimensional electron gases, such as those based on GaAs, in terms of performance at higher temperatures and lower magnetic fields. The bottleneck in the realisation of a turn-key quantum resistance standard requiring minimum user intervention has so far been the need to fine-tune the carrier density in this material to fit the constraints imposed by a simple cryo-magnetic system. Previously demonstrated methods, such as via photo-chemistry or corona discharge, require application prior to every cool-down as well as specialist knowledge and equipment. To this end we perform metrological evaluation of epigraphene with carrier density tuned by a recently reported permanent molecular doping technique. Measurements at two National Metrology Institutes confirm accurate resistance quantisation below 5n-1. Furthermore, samples show no significant drift in carrier concentration and performance on multiple thermal cycles over three years. This development paves the way for dissemination of primary resistance standards based on epigraphene.
© 2019 BIPM & IOP Publishing Ltd.
© 2019 BIPM & IOP Publishing Ltd.
quantum Hall effect
measurement standards
molecular doping
grapheme
Author
Hans He
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Samuel Lara Avila
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
National Physical Laboratory (NPL)
Kyung Ho Kim
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
N. E. Fletcher
National Physical Laboratory (NPL)
S. Rozhko
National Physical Laboratory (NPL)
T. Bergsten
RISE Research Institutes of Sweden
Gunnar Eklund
RISE Research Institutes of Sweden
Karin Cedergren
RISE Research Institutes of Sweden
Rositsa Yakimova
Linköping University
Yung Woo Park
Seoul National University
University of Pennsylvania
Alexander Tzalenchuk
National Physical Laboratory (NPL)
Royal Holloway University of London
Sergey Kubatkin
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Metrologia
0026-1394 (ISSN) 16817575 (eISSN)
Vol. 56 4 045004Subject Categories
Construction Management
Other Electrical Engineering, Electronic Engineering, Information Engineering
Condensed Matter Physics
DOI
10.1088/1681-7575/ab2807