高自旋具有单轴各向异性的横向Ising模型基态相变现象的研究

The ground-state phase transition study of the transverse high-spin Ising model with different single-ion anisotropies

采用平均场理论和相关有效场理论,对高自旋具有单轴各向异性的横向Ising模型的基态相变现象进行了研究,推导出系统有限温度和基态时磁矩与能量公式.采用数值计算方法得到了平均场理论和相关有效场理论下的蜂窝点阵、平方点阵和简立方点阵晶格的基态相图,重点比较了通过平均场理论和相关有效场理论得到的相变特征的差异.

The transverse high-spin Ising model with different single-ion anisotropies is studied in the ground state within the mean field theory and the correlated effective-field theory. The expressions of magnetization and energy in the finite temperature and ground state are derived and the results are got numerically. The ground-state phase diagram is obtained within the mean field theory, and the groundstate phase diagrams for the honeycomb lattice, the square lattice and the simple cubic lattice are gained, respectively, within the correlated effective theory. The focus of this paper is on the difference of phase transition properties within the mean-field theory and the correlated effective-field theory.