|Superuniversality in phase-ordering disordered ferromagnets|
|Henkel M., Pleimling M.|
|Phys. Rev. B78 (2008) 224419|
|DOI : 10.1103/PhysRevB.78.224419|
|ArXiv : arxiv:0807.1485 [PDF]|
The phase-ordering kinetics of the ferromagnetic two-dimensional Ising model with uniform bond disorder is investigated by intensive Monte Carlo simulations. Simple ageing behaviour is observed in the single-time correlator and the two-time responses and correlators. The dynamical exponent z and the autocorrelation exponent lambda_C only depend on the ratio eps/T, where eps describes the width of the distribution of the disorder, whereas a more complicated behaviour is found for the non-equilibrium exponent a of the two-time response as well as for the autoresponse exponent lambda_R. The scaling functions are observed to depend only on the dimensionless ratio eps/T. If the length scales are measured in terms of the time-dependent domain size L(t), the form of the scaling functions is in general independent of both eps and T. Conditions limiting the validity of this `superuniversality' are discussed.