Noise In Nonohmic Regimes Of Disordered Systems

We present here a short review of mainly experimental properties of noise as disordered systems are driven into non-ohmic regimes by applying voltages of few volts only. It is found that the noise does not simply follow the resistance in that the direction of change of noise could be opposite to that of resistance. It is discussed how this and other properties make the noise a complementary and incisive tool for studying complex systems, particularly its dynamic properties. Study of noise in non-ohmic regimes in physical systems is rather in a nascent stage. Some of the open issues are highlighted.