arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1208.0883cond-mat.stat-mechcond-mat.dis-nn
收藏

在铁磁-顺磁过渡线上具有各向异性键随机性的三维伊辛模型的临界行为

Critical Behavior of the Three-Dimensional Ising model with Anisotropic Bond Randomness at the Ferromagnetic-Paramagnetic Transition Line

T. Papakonstantinou, A. Malakis

摘要:

研究了简单立方晶格上具有空间单轴各向异性键随机性的$\pm J$三维伊辛模型。在$xy$平面中应用$\pm J$随机交换,而在z方向上仅使用铁磁交换。在绘制相图并与相应的各向同性情况进行比较后,在铁磁-顺磁过渡线处,使用平行回火和方便的反铁磁键($p_z=0 ; p_{xy}=0.176$)浓度对系统进行了研究。数值结果清楚地表明,该体系存在一个与三维随机伊辛模型属于同一普适类的二阶铁磁-顺磁相变。描述序参量的对数导数的峰值的有效指数的平滑有限尺寸行为提供了临界指数$1/ν=1.463(3)$的准确估计,并且磁化数据的崩溃分析给出了估计$β/ ν=0.516(7)$。这些结果,是在协议与以前的研究,特别是与各向同性的$\pm J$三维伊辛在铁磁-顺磁过渡线,表明引入的各向异性无关。

英文摘要:

We study the $\pm J$ three-dimensional Ising model with a spatially uniaxially anisotropic bond randomness on the simple cubic lattice. The $\pm J$ random exchange is applied in the $xy$ planes, whereas in the z direction only a ferromagnetic exchange is used. After sketching the phase diagram and comparing it with the corresponding isotropic case, the system is studied, at the ferromagnetic-paramagnetic transition line, using parallel tempering and a convenient concentration of antiferromagnetic bonds ($p_z=0 ; p_{xy}=0.176$). The numerical data point out clearly to a second-order ferromagnetic-paramagnetic phase transition belonging in the same universality class with the 3d random Ising model. The smooth finite-size behavior of the effective exponents describing the peaks of the logarithmic derivatives of the order parameter provides an accurate estimate of the critical exponent $1/ν=1.463(3)$ and a collapse analysis of magnetization data gives an estimate $β/ ν=0.516(7)$. These results, are in agreement with previous studies and in particular with those of the isotropic $\pm J$ three-dimensional Ising at the ferromagnetic-paramagnetic transition line, indicating the irrelevance of the introduced anisotropy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑