Magnetization in the case of anisotropic exchange interaction
Magnetization in the case of anisotropic exchange interaction
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DOI：
10.1103/physrevb.69.174431
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发表时间：
2004-05
影响因子：
3.7
通讯作者：
Huai-Yu Wang;Chong-yu Wang;E. Wang
中科院分区：
文献类型：
--
作者：
Huai-Yu Wang;Chong-yu Wang;E. Wang
本文描述了当交换作用在z方向各向异性时，用海森堡模型计算自旋算符统计平均值的三个分量的方法。利用多体格林函数方法，给出了外场同时作用于x和z方向时磁化强度的计算公式，并对自旋值S=1/2、1、3/2、2和5/2时的磁化强度进行了显式推导。在此基础上，给出了任意自旋值时磁化强度的一般计算公式。给出了各向同性和各向异性交换相互作用的数值分析。讨论了三维和二维情况下的计算结果。基于数值结果，我们提出了一种在实验中检验薄膜是否存在交换各向异性成分的方法。
This paper describes a method to calculate the three components of statistical average of spin operators with Heisenberg model when the exchange interaction is anisotropic in z direction. By the use of many-body Green's function method, when external field is applied in both x and z directions, formalism for calculation of magnetization and are explicitly derived for spin value S=1/2, 1, 3/2, 2, and 5/2. Based on the formalism, a general expression for calculation of for any spin value is suggested. Numerical analysis is presented for both cases of isotropic and anisotropic exchange interaction. The results of both three-dimensional and two-dimensional cases are discussed. Based on the numerical results, we suggest a method to test a film in experiments whether there is an ingredient of exchange anisotropy.