da Silva Roberto, Fernandes Henrique A, Drugowich de Felício J R
Instituto de Física, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 - CEP 91501-970, Porto Alegre, Rio Grande do Sul, Brazil.
Coordenação de Física, Universidade Federal de Goiás, Campus Jataí, BR 364, km 192, 3800 - CEP 75801-615, Jataí, Goiás, Brazil.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Oct;90(4):042101. doi: 10.1103/PhysRevE.90.042101. Epub 2014 Oct 1.
We have investigated the dynamic critical behavior of the two-dimensional Z(5)-symmetric spin model by using short-time Monte Carlo (MC) simulations. We have obtained estimates of some critical points in its rich phase diagram and included, among the usual critical lines the study of first-order (weak) transition by looking into the order-disorder phase transition. In addition, we also investigated the soft-disorder phase transition by considering empiric methods. A study of the behavior of β/νz along the self-dual critical line has been performed and special attention has been devoted to the critical bifurcation point, or Fateev-Zamolodchikov (FZ) point. First, by using a refinement method and taking into account simulations out of equilibrium, we were able to localize parameters of this point. In a second part of our study, we turned our attention to the behavior of the model at the early stage of its time evolution in order to find the dynamic critical exponent z as well as the static critical exponents β and ν of the FZ point on square lattices. The values of the static critical exponents and parameters are in good agreement with the exact results, and the dynamic critical exponent z≈2.28 very close to the four-state Potts model (z≈2.29).
我们通过使用短时蒙特卡罗(MC)模拟研究了二维Z(5)对称自旋模型的动态临界行为。我们在其丰富的相图中获得了一些临界点的估计值,并且在通常的临界线中,通过研究有序-无序相变纳入了对一级(弱)相变的研究。此外,我们还通过考虑经验方法研究了软无序相变。我们对沿自对偶临界线的β/νz行为进行了研究,并特别关注了临界分岔点,即法捷耶夫-扎莫洛季科夫(FZ)点。首先,通过使用一种改进方法并考虑非平衡模拟,我们能够确定该点的参数。在研究的第二部分,我们将注意力转向模型在其时间演化早期的行为,以便在正方形晶格上找到FZ点的动态临界指数z以及静态临界指数β和ν。静态临界指数和参数的值与精确结果吻合良好,动态临界指数z≈2.28,非常接近四态Potts模型(z≈2.29)。