含有DM相互作用的混合XXZ模型的临界性质

Critical Behavior of Mixed-Spin XXZ Model with Dzyaloshinsky-Moriya Interaction

利用平均场近似的方法,研究了立方晶格上具有DM相互作用的混合XXZ模型的相变和临界性质.在Ising极限下,在不同的DM相互作用参量D下做出了系统的自发磁化强度m随约化温度T=1/K的变化,得到了系统的临界温度,分析了DM相互作用对系统临界温度的影响;在不同的各向异性参数△下作出了系统二级相变线,结果表明混合自旋XXZ系统只存在二级相变,系统没有出现三临界点.

By using the mean-field approximation method, the critical behavior of the mixed-spin XXZ model with DM interaction on the cubic lattice is studied. In the Ising limit, under DM interaction with the parameter D, spontaneous magnetization m in the system changes with the reduced temperature, so critical temperature is got and the effects of DM interaction to critical temperature is analyzed. Besides, under different anisotropic values, the phase diagrams of the second - ordered phase transition are obtained. The results indicate the mixed - spin system XXZ only presents second phase transition and no tricritical point.