二维磁性系统和准一维磁性纳米管的内能  

Intrinsic Energies of Two-dimensional Heisenberg Magnets and Ferromagnetic Single-walled Nanotubes

作　　者：米斌周[1] 冯翠菊[1] 祁云平[2] 丁东[1] 薛永红[1] 

机构地区：[1]华北科技学院基础部,北京101601 [2]西北师范大学物电学院,甘肃兰州730070

出　　处：《计算物理》2015年第1期86-92,共7页Chinese Journal of Computational Physics

基　　金：中央高校基本科研业务费专项资金(3142012017);河北省教育厅科技基金(A2013024);河北省高等学校科学技术研究项目(QN2014330)资助项目

摘　　要：采用量子统计理论的多体格林函数法计算二维单离子各向异性海森伯铁磁体、反铁磁体以及单壁铁磁纳米管的内能,对比铁磁体和反铁磁体的结果.在相同的参量下,反铁磁能量总是低于相应的铁磁能量(相变点除外).由于反铁磁能量随温度上升的速度较铁磁能量快,当温度升高到居里点TC和奈尔点TN时(TC=TN),铁磁能量和反铁磁能量相等.横向关联效应对系统内能的影响较大,不能忽略.Intrinsic energy of two-dimensional square lattice single-ion anisotropic Heisenberg ferromagnets, antiferromagnets, and ferromagnetic single-walled nanotubes are calculated with many-body Green’ s function method in quantum statistical theory. Calculated results of ferromagnets and antiferromagnets are compared. Between zero temperature and phase transition point, including zero temperature, anti-ferromagnetic energy is always lower than that of ferromagnetic energy. Calculation method of intrinsic energy in this paper is applicable not only to ferromagnetic system, but also suitable for antiferromagnetic system and ferrimagnetic system, as well as ferromagnetic single-walled nanotubes. Intrinsic energies are greatly lower than classical energies, which shows that transverse correlation effect is important.

关 键 词：海森伯模型 二维系统 磁性纳米管 内能 多体格林函数法 

分 类 号：O469[理学—凝聚态物理]