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THU: Thursday Contributed Sessions
THU 13: Poster Session: Applications
THU 13.88: Poster
Donnerstag, 11. September 2025, 16:30–18:30, ZHG Foyer 1. OG
A practical graphene quantum Hall resistance standard for realizing the unit ohm — •Yefei Yin1, Mattias Kruskopf1, Stephan Bauer1, Teresa Tschirner1, Klaus Pierz1, Frank Hohls1, 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
Quantum Hall resistance (QHR) standards play an essential role for the realization of the units ohm, farad, ampere, and kilogram in the revised International System of Units. The primary realization of the unit ohm is still mainly based on GaAs-based QHR standards with the quantized resistance RH = h/2e2 operating at high magnetic flux densities B > 10 T, limited currents I < 50 µA, and low temperatures T < 1.5 K. These operating conditions significantly hinder a wide application of these standards other than at highly specialized national metrology institutes. In this work, we developed practical primary QHR standards based on n- and p-type epitaxial graphene devices operating at relaxed conditions. The presented study systematically demonstrates that p-type epitaxial graphene can be used for primary resistance standards and is as accurate (10−9 accuracy) as GaAs and n-type graphene counterparts for realizing the unit ohm.1 The n-type graphene QHR standards achieved world-class performance with 10−9 accuracy under relaxed conditions (B = 4.5 T, I = 232.5 µA, and T = 4.2 K).2−3 [1] Appl. Phys. Lett., 125, 064001 (2024); [2] Adv. Phys. Res. 1, 2200015 (2022). [3] Phys. Rev. Applied, 23, 014025 (2025)
Keywords: quantum electrical metrology; quantum Hall resistance standard; quantum Hall effect; epitaxial graphene