低温下自旋为1/2的海森伯亚铁磁棱型链的1/3磁化平台  

THE 1/3 MAGNETIZATION PLATEAU OF A SPIN-1/2 HEISENBERG FERRIMAGNETIC DIAMOND CHAIN AT LOW TEMPERATURE

作　　者：王金刚[1] 成泰民[2] 

机构地区：[1]沈阳航空航天大学,沈阳110136 [2]沈阳化工大学数理系,沈阳110142

出　　处：《低温物理学报》2014年第4期298-304,共7页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:11374215);吉林大学超硬材料国家重点实验室开放课题资助项目(批准号:201304)资助的课题~~

摘　　要：本文利用Jordan-Wigner变换和不变本征算符法计算了低温下自旋为1/2的海森伯亚铁磁棱型链系统的元激发谱,得到了三支没有简并的元激发谱.利用不变本征算符法对系统的哈密顿量进行了对角化,并导出有限温度和外磁场下的系统的配分函数及磁化强度.在绝对零度与有限温度下,通过分析诸交换积分(J1,J2,J3,Jm)对系统的磁化强度随外磁场的变化规律,得到了系统的三个临界磁场强度(HCB,HCE,HCS),并从三支元激发的性质说明了三个临界磁场强度起源及系统的磁化强度随外磁场变化出现1/3磁化平台的起因.The elementary excitations spectra in the system of a spin-1/2 Heisenberg ferrimagnetic diamond chain at low temperature were calculated by Jordan-Wigner transformations and invariant eigen-operator method. And three non-degenerate elementary excitations spectra were obtained. The Hamiltonian of the system was diagonalized with invariant eigen-operator method, and the partition function and magnetization of the system at finite temperature and external magnetic field were derived as well. By analyzing the changing rule of every exchange integral （J1, J2, J3, Jm） to magnetization of the system with external magnetic field at absolute zero and finite temperature, three critical magnetic field intensities （HcB, HcE, Hcs） of the system were obtained, explaining the origin of three critical magnetic field intensities and the occurrence of 1/3 magnetization plateau when magnetization of the system changing with external magnetic field from the property of three elementary excitations.

关 键 词：不变本征算符法 JORDAN-WIGNER变换 临界磁场强度 磁化强度 

分 类 号：O441.2[理学—电磁学]