Physical review. B, Condensed matter
Noise exponents of the random resistor network
Youngah Park, A. Brooks Harris, T. C. Lubensky
Abstract
We consider the critical properties of the two-point resistance and its fluctuations due to microscopic noise in a randomly diluted resistor network near the percolation threshold ${p}_{c}$. We introduce a n\ifmmode\times\else\texttimes\fi{}m replicated Hamiltonian in order to treat separately the configuration average over the randomly occupied bonds denoted [ ${]}_{\mathrm{av}}$ and the average over probability distribution function of the fluctuating microscopic bond conductance, denoted { ${\mathrm{}}}_{f}$. We evaluate a family of exponents {${\ensuremath{\psi}}_{l}$} (l=2,3,. . .) whose values are 1+O(\ensuremath{\epsilon}) with \ensuremath{\epsilon}=6-d where d is the spatial dimensionality. Each ${\ensuremath{\psi}}_{l}$ governs the critical behavior of the lth cumulant of the resistance between the sites x,x' conditionally averaged subject to the sites being in the same cluster such that ${C}_{R}$\ifmmode\bar\else\textasciimacron\fi{} $^{(l)}$(x,x')\ensuremath{\sim}\ensuremath{\Vert}x- for p near ${p}_{c}$, where ${\ensuremath{\nu}}_{p}$ is the correlation-length exponent for percolation. Furthermore, ${\ensuremath{\psi}}_{2}$=1+\ensuremath{\epsilon}/105 determines the dependence of the variance of the resistance in a finite network on size L as . .AE