Berlin 2024 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 109: Focus Session: Proximity Effects in Epitaxial Graphene II
O 109.8: Vortrag
Freitag, 22. März 2024, 12:45–13:00, MA 141
long-term stable epitaxial graphene-based quantum Hall resistance standard for operating under relaxed conditions — •Yefei Yin1, 2, Mattias Kruskopf1, Pierre Gournay3, Benjamin Rolland3, Martin Götz1, Eckart Pesel1, Davood Momeni1, Frank Hohls1, Klaus Pierz1, Hansjörg Scherer1, Rolf J. Haug2, and Hans W. Schumacher1 — 1Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany — 2Institut für Festkörperphysik, Leibniz Universität Hannover, 30167, Hannover, Germany — 3Bureau International des Poids et Mesures (BIPM), Pavillion de Breteuil, 92312 Sevres, France
The epitaxial graphene-based quantum Hall resistance standard (QHRS) has excellent potential for resistance metrology due to its large Landau level gap and strong Fermi level pinning. However, since as-grown epitaxial graphene has an electron density of 1013 cm−2, permanent control of the carrier density and maintenance of the Hall resistance quantization are essential for practical graphene-based QHRS. This desirable goal is now achievable through the molecular doping by spin-coating F4-TCNQ dopant stacks on the graphene surface [1]. Our graphene-based QHRS show a Hall resistance quantization with an accuracy of (2± 2)× 10−9 (k=2) under relaxed conditions of B = 4.5 T, I = 232.5 µA, and T= 4.2 K simultaneously. The accurate quantization has not shown any signs of degradation over two years, so far. Furthermore, the graphene-based QHRS has maintained quantization accuracy despite shipping between PTB and BIPM.[1] Y. Yin, et al., Adv. Physics Res. 1, 2200015 (2022)
Keywords: epitaxial graphene; quantum Hall resistance standard; quantum Hall resistance metrology; graphene functionlization; F4-TCNQ molecular doping