计算物理 ›› 1988, Vol. 5 ›› Issue (1): 107-112.

• 论文 • 上一篇    下一篇

二维Spin Glass系统——随机格点SO(3)自旋模型的Monte Carlo模拟

应和平, 董绍静, 杨清健   

  1. 浙江大学物理系
  • 收稿日期:1987-08-03 出版日期:1988-03-25 发布日期:1988-03-25

MONTE CARLO SIMULATION OF A NEW SO(3) SPIN GLASS MODEL ON THE 2-DIMENSIONAL RANDOM LATTICES

Ying He-Ping, Dong Shao-Jing, Yang Qing-Jan   

  1. Dept. of Physics, zhejiang university
  • Received:1987-08-03 Online:1988-03-25 Published:1988-03-25

摘要: 本文提出了一种定义在二维随机格点上的Spin Glass模型——具有±JO Frustration效应的SO(3)自旋系统。利用Monte Carlo方法计算了系统的平均内能,比热和拓扑激发等参量,并考察了系统的热滞过程、有限格点效应以及混合相跑动,以确定系统的相变规律。结果表明,此自旋系统不存在一阶和二阶相变过程。但发生由于拓扑涡旋凝聚引起的高阶相变,从而显示出与Spin Glass低温特性密切相关的Frustration和无序现象。此模型可能为研究Spin Glass磁性系统提出了一条新的途径。

Abstract: A new spin glass model defined on the N×N 2-dimensional random lattice with the SO (3) spin variables is proposed, and. studied by Monte Carlo simulations. The thermodanamics, such as the internal energy and specific heat per spin and the topological excition are calculated. The thermal hysteresis and mix-phase runs are also made to obtain some information of the Phase transitions. A higher-order, instead of the usual first-or second-order, Phase transition due to the vortex condensation is found. Moreover, the results show the important frustration and disorder effects which are main causes of low-temperature properties of sPin glass.