零温下在布里渊区边界二维绝缘铁磁体的磁振子软化

The Magnon-softening of Two Dimensional Insulating Ferromagnet at the Boundary of Brillouin Zone at Absolute Zero Temperature

在二维正方绝缘铁磁系统基础上建立一个磁振子-声子相互作用模型.利用格林函数方法研究磁振子-声子相互作用下的二维绝缘铁磁体的磁振子谱,计算布里渊区边界的主要对称点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,并讨论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 in two dimensional insulating ferromagnet. By using Matsubara Green function theory, we have studied the magonon spectrum, and calculated the magnon dispersion curve on the main symmetric point and line in the boundary of 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.