Roy Parna, Sen Parongama
Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009, India.
Phys Rev E. 2017 Feb;95(2-1):020101. doi: 10.1103/PhysRevE.95.020101. Epub 2017 Feb 7.
We explore the effect of interplay of interfacial noise and curvature-driven dynamics in a binary spin system. An appropriate model is the generalized two-dimensional voter model proposed earlier [M. J. de Oliveira, J. F. F. Mendes, and M. A. Santos, J. Phys. A: Math. Gen. 26, 2317 (1993)JPHAC50305-447010.1088/0305-4470/26/10/006], where the flipping probability of a spin depends on the state of its neighbors and is given in terms of two parameters, x and y. x=0.5andy=1 correspond to the conventional voter model which is purely interfacial noise driven, while x=1 and y=1 correspond to the Ising model, where coarsening is fully curvature driven. The coarsening phenomena for 0.5<x<1 keeping y=1 is studied in detail. The dynamical behavior of the relevant quantities show characteristic differences from both x=0.5 and 1. The most remarkable result is the existence of two time scales for x≥x_{c} where x_{c}≈0.7. On the other hand, we have studied the exit probability which shows Ising-like behavior with a universal exponent for any value of x>0.5; the effect of x appears in altering the value of the parameter occurring in the scaling function only.
我们研究了二元自旋系统中界面噪声和曲率驱动动力学相互作用的影响。一个合适的模型是之前提出的广义二维选民模型[M. J. 德奥利维拉、J. F. F. 门德斯和M. A. 桑托斯,《物理学杂志A:数学一般》26, 2317 (1993)JPHAC50305 - 447010.1088/0305 - 4470/26/10/006],其中一个自旋的翻转概率取决于其相邻自旋的状态,并由两个参数x和y给出。x = 0.5且y = 1对应于纯粹由界面噪声驱动的传统选民模型,而x = 1且y = 1对应于伊辛模型,其中粗化完全由曲率驱动。详细研究了在y = 1时0.5 < x < 1的粗化现象。相关量的动力学行为与x = 0.5和x = 1时均表现出特征差异。最显著的结果是对于x≥xc(其中xc≈0.7)存在两个时间尺度。另一方面,我们研究了退出概率,对于任何x > 0.5的值,其表现出具有通用指数的类伊辛行为;x的影响仅体现在改变标度函数中出现的参数值上。