有反铁磁近邻作用的海森堡铁磁长程作用自旋链的低温性质的修正自旋波理论研究  

Modified spin wave theory applied to the low-temperature properties of ferromagnetic long-range interacting spin chain with the antiferromagnetic nearest-neighbor interaction

作　　者：张修志 陈渊[1] ZHANG Xiu-zhi;CHEN Yuan(School of Physics and Materials Science,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]广州大学物理与材料科学学院,广东广州510006

出　　处：《广州大学学报（自然科学版）》2022年第3期55-66,共12页Journal of Guangzhou University:Natural Science Edition

基　　金：Supported by National Natural Science Foundation of China (11604059);Science and Technology Program of Guangzhou;China (202002030274)。

摘　　要：文章将修正的自旋波理论应用于研究具有铁磁长程相互作用J0/rp和反铁磁近邻相互作用J的海森堡铁磁链.通过限制总磁化强度为零,利用自洽方法得到了系统的自旋波热力学.结果表明,铁磁长程相互作用和反铁磁近邻相互作用对系统的低温性质有很大的影响.比热C和比热系数C/T(1/(p-1))均呈现受p与J诱导的低温峰值行为,而磁化率系数χT2显示了有一最小值,且受p与J诱导的低温行为.当J=0时,且在大p极限下,本文的结果与精确贝特方案的结果和量子蒙特卡罗数据吻合得很好.In this paper, the modified spin-wave theory is applied to the Heisenberg ferromagnetic chain with the ferromagnetic long-range interaction J_(0)/r^(p) and antiferromagnetic nearest-neighbor interaction J. The spin-wave thermodynamics of the system are obtained within the self-consistent method by constraining the total magnetization to be zero. It is shown that the ferromagnetic long-range and antiferromagnetic nearest-neighbor interactions have great influence on the low-temperature properties of the system. At low temperatures, it is found that the specific heat C exhibits the temperature-dependent peak behavior which is induced by p and J, along with the specific heat coefficient C/T^(1/(p-1));while the susceptibility coefficient χT^(2) shows the low-temperature behavior with a minimum induced by p and J. For J=0 and in the large-p limit, our results agree well with the exact Bethe ansatz results and the quantum Monte Carlo data.

关 键 词：修正自旋波理论 海森堡铁磁链 长程相互作用 最近邻相互作用 

分 类 号：O482.52[理学—固体物理]