Nonequilibrium phase transitions and tricriticality in a three-dimensional lattice system with random-field competing kinetics
Abstract
We study a nonequilibrium Ising model that stochastically evolves under the simultaneous operation of several spin-flip mechanisms. In other words, the local magnetic fields change sign randomly with time due to competing kinetics. This dynamics models a fast and random diffusion of disorder that takes place in dilute metallic alloys when magnetic ions diffuse. We performe Monte Carlo simulations on cubic lattices up to L=60. The system exhibits ferromagnetic and paramagnetic steady states. Our results predict first-order transitions at low temperatures and large disorder strengths, which correspond to the existence of a nonequilibrium tricritical point at finite temperature. By means of standard finite-size scaling equations, we estimate the critical exponents in the low-field region, for which our simulations uphold continuous phase transitions.
Keywords
Cite
@article{arxiv.1004.2065,
title = {Nonequilibrium phase transitions and tricriticality in a three-dimensional lattice system with random-field competing kinetics},
author = {Nuno Crokidakis},
journal= {arXiv preprint arXiv:1004.2065},
year = {2015}
}
Comments
14 pages, 7 figures, accepted for publication in Phys. Rev. E