Resistance Standard Based on the Quantized Hall Effect

摘要

The thesis contains a treatise on the application of the Quantum Hall Effect (QHE) as a resistance standard. Starting from the assumption that the steps in the Hall resistance are given by h/i(e squared) with an accuracy of better than 1:10 to the 8th power, a reproducibility of the same order has been aimed at. To this end, the authors have paid attention to both the properties of the QHE samples and the measurement setup. Part 1 is concerned with possible deviations of the measured quantized Hall resistance as a function of temperature and current, and several properties of the samples (AlGaAs-GaAs heterostructures). Part 2 starts with a short introduction (chapter 6) concerning the choice of a type of measurement setup. The cryogenic current comparator turns out to be the best choice. Chapter 7 contains a description of a potentiometric bridge capable to relate the quantized Hall resistance to a resistance of nominally the same value. In chapter 8, a description is presented of a universal cryogenic resistance bridge that is capable to relate the quantized Hall resistance (about 13 k(ohm) to a resistor of 1 ohm (national primary resistance standard) in only two steps. The sensitivity of the heart of this bridge, the cryogenic current comparator, has been increased by a factor of 3. This is described in chapter 9, where also an expression is derived for calculating the sensitivity.