Addition of the one-dimensional quantised ballistic resistance

Abstract

The authors present experimental results showing that the quantised nature of the ballistic resistance in narrow channels is preserved when the electrons pass ballistically through two narrow constrictions. As the width of each narrow channel is varied independently, the resistance of the pair is equal to the resistance of the narrowest; this is explained by the conservation of quantum (sub-band) number. The absolute quantisation is not as accurate as observed in a single constriction and is modified by an anomalous resistance whose origin the authors discuss.