Mesoscopic conductors and correlations in laser speckle patterns.

Submicrometer disordered metallic systems at low temperatures display interesting conductance fluctuation effects, owing to the interference of coherent electron wave transmission through the system. This quantum interference phenomenon also gives rise to the striking experimental observation that the 1/f noise power (where f is frequency) in disordered conductors increases as the temperature is decreased, contrary to common intuition. The theoretical techniques developed for this problem can be applied to the transmission of light through a random medium, and this yields novel predictions for the correlations in the laser speckle patterns and the possibility of studying the positions and motions of scatterers in a medium which multiply scatter the probing light.