Relaxational dynamics in 3D randomly diluted Ising models

Abstract

We study the purely relaxational dynamics (model A) at criticality in three-dimensional disordered Ising systems whose static critical behaviour belongs to the randomly diluted Ising universality class. We consider the site-diluted and bond-diluted Ising models, and the +- J Ising model along the paramagnetic-ferromagnetic transition line. We perform Monte Carlo simulations at the critical point using the Metropolis algorithm and study the dynamic behaviour in equilibrium at various values of the disorder parameter. The results provide a robust evidence of the existence of a unique model-A dynamic universality class which describes the relaxational critical dynamics in all considered models. In particular, the analysis of the size-dependence of suitably defined autocorrelation times at the critical point provides the estimate z=2.35(2) for the universal dynamic critical exponent. We also study the off-equilibrium relaxational dynamics following a quench from T=\infty to T=T_c. In agreement with the field-theory scenario, the analysis of the off-equilibrium dynamic critical behavior gives an estimate of z that is perfectly consistent with the equilibrium estimate z=2.35(2).

38 pages

References in corpus (5)

• The 3D +-J Ising model at the ferromagnetic transition line
• Magnetic-glassy multicritical behavior of the three-dimensional +- J Ising model
• Calculations of the dynamical critical exponent using the asymptotic series summation method
• Computer simulation of the critical behavior of 3D disordered Ising model
• Local and cluster critical dynamics of the 3d random-site Ising model

Cited by in corpus (3)

• The critical behavior of three-dimensional Ising spin glass models
• Static and dynamic structure factors in three-dimensional randomly diluted Ising models
• Critical and multicritical behavior of the +- J Ising model in two and three dimensions