PHYSICS AND APPLICATION OF THE QUANTUM HALL-EFFECT

The High Magnetic Field Laboratory in Grenoble is the birthplace of the quantum Hall effect (QHE). In the morning of the 5th of February 1980 - during a magnetotransport experiment on silicon field-effect transistors - the idea came up to measure deviations of the Hall resistance relative to a quantized value which can be calculated on the basis of a simple one-electron picture. The analysis of the experimental data showed immediately that the deviations are unmeasurably small and today it is generally accepted that the quantized Hall resistance depends exclusively on fundamental constants. This result opened a new research field. In this paper only recent developments in the application of the QHE in metrology and the connection of the quantized Hall resistance with the quantization of the resistance of quantum point contacts, which was discovered in 1988, will be summarized.