Noise in Non-Ohmic Regimes of Disordered Systems

Abstract

Disordered systems in general are driven into non-ohmic regimes under a sufficiently large bias. Resistivity either decreases or increases depending upon the transport mechanism that comes into play. The non-ohmicity leads to current redistribution which is expected to have strong effect on the associated noise. It is found that the noise does not simply follow the resistance. It does vary as the resistance but is controlled by parameters different from those responsible for the onset of non-ohmicity. Such property makes the noise an important tool for studying complex systems such as disordered ones, specially in the non-ohmic regimes. There are also other unique properties in time and frequency domains. An attempt will be made to review these properties in relation with those in the ohmic regimes.