摘要
在二维复式正方Heisenberg铁磁系统的基础上建立了磁振子-声子相互作用模型.利用松原格林函数理论研究了系统的磁激发,计算了布里渊区的主要对称点线上的磁振子色散曲线,比较了光频支声子与声频支声子对系统磁激发的影响以及各项参数的变化对磁振子软化的影响.发现光频支声子-磁振子耦合对磁振子软化起主要作用,尤其是纵向光频支声子对磁振子软化起更大的作用,并且非磁性离子的光频支声子对磁振子软化的作用比磁性离子的光频支声子对磁振子软化的作用更显著.
A magnon-phonon interaction model is built in the two-dimensional double square ferromagnetic system. By using Matsubara Green function theory, we study magnetic excitation of the system, and calculate the magnon dispersion curve on the main symmetric points and lines in the Brillouin zone. The influences of optical phonon and acoustic phonon on the magnetic excitation of the system are compared, and the influences of the parameter change on the magnon softening are also studied. It is concluded that the coupling of the optical phonon and magnon has predominant effect on the magnon softening, especially the longitudinal optical phonon has the greatest effect on the magnon softening, and the effect of nonmagnetic ion on magnon softening is stronger than that of magnetic ion.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第6期2941-2948,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:59972005)
高等学校博士学科点基金(批准号:98014513)
辽宁省教育厅高等学校科学研究基金(批准号:2005325)资助的课题~~
关键词
磁振子-声子相互作用
磁振子软化
磁激发
光频支声子
铁磁系统
magnon-phonon interaction, magnon softening, magnetic excitation, optical phonon, ferromagnetic system