Sub-Poissonian Shot Noise In A Diffusive Conductor
  A review is given of the shot-noise properties of metallic, diffusive conductors. The shot noise is one third of the Poisson noise, due to the bimodal distribution of transmission eigenvalues. The same result can be obtained from a semiclassical calculation. Starting from Oseledec's theorem it is shown that the bimodal distribution is required by Ohm's law. 
M. J. M. de Jong and C. W. J. Beenakker