Cluster evolution in a cold Ising ferromagnet: Disappearance of magic numbers with temperature rise
Cluster evolution in a cold Ising ferromagnet: Disappearance of magic numbers with temperature rise
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DOI：
10.1103/physrevb.77.024303
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发表时间：
2008-01-01
影响因子：
3.7
通讯作者：
Kooi, B. J.
中科院分区：
文献类型：
--
作者：
Kooi, B. J.
基于二维方形晶格Ising模型的簇在低温和中温下的衰变和生长已经用蒙特卡罗模拟研究，采用Glauber（或Metropolis）动力学，利用一个过程，其中开始配置是一个簇（倾向于在外加磁场中生长）在一个相对较小的晶格上。这种集群的行为是随机的，只有当分析了数千个典型的相同集群时，其潜在的确定性行为才会变得明显。在0.4T(c)时，随时间变化的簇大小分布相对较宽，但平滑，即高斯分布，比较了各种相对紧凑的簇的衰减和生长行为。在较低的温度下，尺寸分布的调制发生在最小值处，对应于n=mx +1和n=mx(m+1)+1，具有m个整数值。定量分析了调制幅度随温度的变化规律。此外，大小分布和内部簇键数（或簇周长）之间的关系也被仔细研究。
Decay and growth of clusters at low and intermediate temperatures based on the two-dimensional square-lattice Ising model has been studied with Monte Carlo simulations employing Glauber (or Metropolis) dynamics, exploiting a procedure where the starting configuration is a cluster (that tend to grow in the applied magnetic field) on a relatively small lattice. The behavior of such a cluster is stochastic and only when typical several thousands of identical clusters are analyzed will the underlying deterministic behavior become apparent. At 0.4T(c), the time-dependent cluster size distribution is relatively broad, but smooth, i.e., Gaussian, and the decay and growth behaviors of various relative compact clusters are compared. At lower temperatures, modulations in the size distribution occur with minima at magic sizes corresponding to n=mxm+1 and n=mx(m+1)+1 with m integer values. A quantitative analysis of the amplitude of the modulations as a function of temperature is performed. Also the relation between the distributions of size and of the number of internal cluster bonds (or cluster perimeter) is scrutinized.