arXiv:cond-mat/0506644 · Physical Review B
Critical dynamics and effective exponents of magnets with extended impurities
Viktoria Blavatska, M. Dudka, R. Folk, Yurij V. Holovatch
Abstract
We investigate the asymptotic and effective static and dynamic critical behavior of $(d=3)$-dimensional magnets with quenched extended defects, correlated in ${\ensuremath{\epsilon}}_{d}$ dimensions (which can be considered as the dimensionality of the defects) and randomly distributed in the remaining $d\ensuremath{-}{\ensuremath{\epsilon}}_{d}$ dimensions. The field-theoretical renormalization-group perturbative expansions being evaluated naively do not allow for the reliable numerical data. We apply the Chisholm-Borel resummation technique to restore convergence of the two-loop expansions and report the numerical values of the asymptotic critical exponents for the model $A$ dynamics. We discuss different scenarios for static and dynamic effective critical behavior and give values for corresponding nonuniversal exponents.