Uncovering the secrets of the 2D random-bond Blume-Capel model

作者：Malakis A^*; Berker A Nihat; Hadjiagapiou I A; Fytas N G; Papakonstantinou T

来源：Physica A: Statistical Mechanics and Its Applications , 2010, 389(15): 2930-2933.

DOI：10.1016/j.physa.2009.12.064

• Random-bond Blume-Capel model

The effects of bond randomness on the ground-state structure, phase diagram and critical behavior of the square lattice ferromagnetic Blume-Capel (BC) model are discussed. The calculation of ground states at strong disorder and large values of the crystal field is carried out by mapping the system onto a network and we search for a minimum cut by a maximum flow method. At finite temperatures the system is studied by an efficient two-stage Wang-Landau (WL) method for several values of the crystal field, including both the first- and second-order phase transition regimes of the pure model. We attempt to explain the enhancement of ferromagnetic order and we discuss the critical behavior of the random-bond model. Our results provide evidence for a strong violation of universality along the second-order phase transition line of the random-bond version.

• 出版日期2010-8-1