Universal conductance fluctuations in three dimensional metallic single crystals of Si
In this paper we report the measurement of conductance fluctuations in 3D crystals of Si made metallic by heavy doping. ( L/L(straight phi) approximately 10(3), where L(straight phi) 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(3)(straight phi) were found to be saturated at <(deltaG(straight phi))(2)> approximately (e(2)/h)(2). An accurate knowledge of the level of disorder enables us to calculate the change in conductance deltaG1 due to movement of a single scatterer as <(deltaG1)(2)> approximately (e(2)/h)(2), which is approximately 2 orders of magnitude higher than its theoretically expected value in 3D systems.