Scaling and self-averaging in the three-dimensional random-field Ising model

We investigate, by means of extensive Monte Carlo simulations, the magnetic critical behavior of the three-dimensional bimodal random-field Ising model at the strong disorder regime. We present results in favor of the two-exponent scaling scenario, <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\bar{\eta}$</EquationSource> </InlineEquation>=2η, where η and <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\bar{\eta}$</EquationSource> </InlineEquation> are the critical exponents describing the power-law decay of the connected and disconnected correlation functions and we illustrate, using various finite-size measures and properly defined noise to signal ratios, the strong violation of self-averaging of the model in the ordered phase. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011