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.

quantum Hall effect

measurement standards

molecular doping



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


0026-1394 (ISSN) 16817575 (eISSN)

Vol. 56 4 045004

Subject Categories

Construction Management

Other Electrical Engineering, Electronic Engineering, Information Engineering

Condensed Matter Physics



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