低温下自旋为1/2的X-Y亚铁磁棱型链的元激发谱  

Elementary Excitations Spectrum in the System of a Spin-1/2 One-dimensional X-Y Mferrimagnetic Diamond-like Chain at Low Temperature

作　　者：成泰民[1] 王蕴鹏[1] 

机构地区：[1]沈阳化工大学数理系,辽宁沈阳110142

出　　处：《沈阳化工大学学报》2012年第3期270-274,共5页Journal of Shenyang University of Chemical Technology

基　　金：国家自然科学基金(10647138);辽宁省教育厅科学研究项目(20060667)

摘　　要：利用Jordan-Wigner变换和不变本征算符法计算低温下自旋为1/2的一维X-Y模型亚铁磁棱型链系统的元激发谱和对应的本征态.得到3支没有简并的元激发谱,其对应的本征态函数之间又相互正交归一.利用不变本征算符法对系统的Hamiltonian进行了退耦,其退耦合过程比常规的幺正变换法便捷,而且直接在系统的能量自表象上自动退耦,因此,这对计算系统的配分函数而言非常便捷.并讨论了不变本征算符法的优缺点.The elementary excitations spectrums and its corresponding eigenstates in the system of a spin-l/2 one-dimensional X-Y model ferrimagnetic diamond-like chain at low temperature were calculated by Jordan-Wigner transform and invariant eigen-operator method. Three non-degenerate elementary excita- tions spectrum were obtained, and its corresponding eigenstate functions were orthonormalized. The Hamil- tonian of the system was decoupled with invariant eigen-operator method, and the decoupling process was more convenient than conventional unitary transformation method. And it was automatically decoupled di- rectly from self-representation of the system, thus it was very convenient to calculate partition function of the system. The advantages or deficiencies of invariant eigen-operator method were discussed in this paper.

关 键 词：不变本征算符法 幺正变换 元激发谱 自旋为1/2的一维亚铁磁棱型链系统 

分 类 号：O482.52[理学—固体物理]