Physical review. B, Condensed matter
Critical amplitudes for correlated percolation
Bosiljka Tadić, R. Pirc
Abstract
We consider the q-state Potts model with correlated random interactions such that their correlations decay at large distances as \ensuremath{\sim}${R}^{\mathrm{\ensuremath{-}}(d\mathrm{\ensuremath{-}}a)}$. Applying the renormalization group and a double (\ensuremath{\epsilon},${\ensuremath{\epsilon}}_{a}$) expansion, we derive the scaling form of the equation of state to linear order in \ensuremath{\epsilon}=6-d and ${\ensuremath{\epsilon}}_{a}$=a-2. In the limit q\ensuremath{\rightarrow}1, which describes correlated percolation, the critical amplitudes ${A}^{\ifmmode\pm\else\textpm\fi{}}$ associated with the mean number of clusters F\ensuremath{\sim}${A}^{\ifmmode\pm\else\textpm\fi{}}$\ensuremath{\Vert}t${\ensuremath{\Vert}}^{2\mathrm{\ensuremath{-}}\ensuremath{\alpha}}$ are shown to diverge when \ensuremath{\alpha} approaches a negative integer as a function of ${\ensuremath{\epsilon}}_{a}$.