New results for the magnitude of flicker noise, considered as resistance fluctuations, in random resistor networks are reported. Near the percolation threshold $p_c$, the magnitude of the relative noise is shown to diverge as ${(p-p_c)}^{-\kappa }$. The new exponent $\kappa$ is calculated by various methods: Monte Carlo simulations, effective-medium theory, and position-space renormalization group. Exponents pertaining to higher-order cumulants of the resistance fluctuations are also calculated. The possible implications of our results for ongoing experiments on metal-insulator mixtures and cermets are also discussed.

• Received 10 December 1984

DOI:https://doi.org/10.1103/PhysRevLett.54.1718