The theory of quantised resistance in narrow constrictions

Abstract
A model is proposed to explain new results showing quantised resistance in narrow constrictions. From the description of the experimental situation it is clear that localisation effects cannot be responsible for the quantisation, so localising mechanisms are not present in the model. It is shown within linear response theory for zero temperature that the two-point resistance, Rc, of a narrow system is exactly quantised: Rc=h/(s(B)e2N), where s(B=0)=2 and s(B not=0)=1, B is the magnetic field and N is a whole number.