Conductance fluctuations near the localized-to-extended transition in narrow Si MOSFETs.

A simple and elegant theoretical picture has emerged to explain the fluctuations in the conductance of disordered, one-dimensional conductors. At zero temperature T, the resonant-tunneling model of Azbel predicts exponentially large fluctuations as the Fermi energy, E sub F, is varied. As T is raised, the fluctuations remain exponentially large, but are the result of one-dimensional phonon-assisted hopping. At still higher T, the inelastic diffusion length L sub (in) becomes as short as the localization length. For temperatures above this localized- to-extended transition, the fluctuations are always of order e sup 2 /h in a sample of length L sub (in). We present the results of experiments on narrow (~70nm) inversion layers in Si MOSFETs.