English

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

Statistical Mechanics 2015-05-14 v1 Disordered Systems and Neural Networks

Abstract

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. In 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.

Keywords

Cite

@article{arxiv.0912.4586,
  title  = {Uncovering the secrets of the 2d random-bond Blume-Capel model},
  author = {A. Malakis and A. Nihat Berker and I. A. Hadjiagapiou and N. G. Fytas and T. Papakonstantinou},
  journal= {arXiv preprint arXiv:0912.4586},
  year   = {2015}
}

Comments

6 LATEX pages, 3 EPS figures, Presented by AM at the symposium "Trajectories and Friends" in honor of Nihat Berker, MIT, October 2009