零温下在Δ线二维绝缘铁磁体的磁振子软化

The softening of Magnon of Two Dimensional Insulating Ferromagnetism on the Δ Line under Absolute Zero Temperature

在二维正方绝缘铁磁系统基础上建立了一个磁振子-声子相互作用模型.利用格林函数方法研究了磁振子-声子相互作用下的二维绝缘铁磁体的磁振子谱,计算了布里渊区的Δ线上的磁振子色散曲线.发现在布里渊区边界区域磁振子谱的软化和磁振子谱线增宽最明显.比较了纵向声子与横向声子对磁振子谱的软化与磁振子谱线增宽的影响,也讨论了各项参数的变化对磁振子谱的软化与磁振子谱线增宽的影响.

A magnon -phonon interaction model is built on two dimensional insulating ferromagnetic. By using Matsubara Green function theory, we have studied the magonon spectrum and calculated the magnon dispersion curve on the A line in the Brillouin Zone for different parameters in the system. It is concluded that at the boundary of Brillouin Zone there is a strong broadening in the magnon linewidth and softening. The influences of longitudinal phonon and transverse phonon on the softening and broadening in the magnon linewidth are compared, and the influences of the parameters are also illustrated.