Universal conductance fluctuations in three dimensional metallic single crystals of Si

Abstract

In this paper we report the measurement of conductance fluctuations in 3D crystals of Si made metallic by heavy doping. (L/L_φ∼10³, where L_φ is the phase coherence length.) Temperature and magnetic field dependence of noise strongly indicate the universal conductance fluctuations as a predominant source of the observed magnitude of noise. Conductance fluctuations within a single phase coherent region of L_φ³ were found to be saturated at <(δG_φ)²>≈(e²/h)². An accurate knowledge of the level of disorder enables us to calculate the change in conductance δG₁ due to movement of a single scatterer as <(δG₁)²>∼(e²/h)², which is ∼2 orders of magnitude higher than its theoretically expected value in 3D systems.