Scattering theory of thermal and excess noise in open conductors

Abstract

Thermal fluctuations at equilibrium and excess fluctuations in the presence of transport in open multiprobe conductors are related to the scattering matrix of the conductor. The fluctuation-dissipation theorem for multiprobe conductors is discussed. A general expression for the excess noise in the presence of transport is derived. These results are applied to conductors which exhibit the quantized Hall effect. If backscattering is suppressed, excess noise is also suppressed. © 1990 The American Physical Society.