Universal Conductance Fluctuations in Narrow Channel Mosfets

Abstract

Mesoscopic normal-metal wires and rings exhibit random, reproducible fluctuations in the magnetoconductance (MC) G(B) due to quantum interference of electron waves [1,2]. These fluctuations are called universal conductance fluctuations (UCF) because at zero temperature their magnitude is of order of e ²/h, regardless of the degree of disorder and the sample size. The fluctuation pattern is sensitive to the microscopic distribution of elastic scatterers for electrons and therefore the fluctuation traces are sometimes referred to as magneto-fingerprints. At finite temperature the size of the sample usually exceeds the inelastic diffusion length L _in of the electrons, and due to classical self-averaging the magnitude of the fluctuations is reduced.