Application of the quantum Hall effect to resistance metrology

The quantum Hall effect (QHE) discovery has revolutionized metrology by providing with a representation of the unit of resistance, R-K, that can be reproduced within a relative uncertainty of one part in 10(9) and is theoretically only linked to Planck's constant h and the electron charge e. This breakthrough also results from the development of resistance comparison bridges using cryogenic current comparator (CCC). The QHE experimental know-how now allows the realization of perfectly quantized Quantum Hall Array Resistance Standards (QHARS) by combining a large number of single Hall bars. In the context of an evolution of the Systeme International (SI) of units by fixing some fundamental constants of physics, the determination of the von Klitzing constant R-K through the use of the so-called Thompson-Lampard calculable capacitor and the realization of refined universality tests of the QHE are of prime importance. Finally, the fascinating graphene material might be a new turning point in resistance metrology. (C) 2011 Published by Elsevier Masson SAS on behalf of Academie des sciences.