I F NOISE NEAR THE METAL-INSULATOR-TRANSITION

The 1/f noise level in polycrystalline indium oxide thin films and of zinc oxide accumulation layers is found to be much higher than that us ually observed in metals. A systematic study of the flicker noise prop erties in these systems reveals a correlation between the 1/f noise ma gnitude and the Proximity of the system to the insulating phase. In fa ct, the noise appears to increase dramatically close to the Anderson t ransition but when the average transport properties exhibited by the s ystem are still diffusive. For static disorder that exceeds the critic al value characterized by K(F)l congruent-to 1 the system exhibits ins ulating behavior and the noise level saturates at a rather high, but d isorder independent value. The similarity of these findings to the beh avior of the magnetic-field-induced Conductance Fluctuations in this s ystem will be pointed out to suggest a common physical origin. This le ads to the prediction of high levels of 1/f in all electronic systems that are close to the metal-insulator transition.