中文摘要：

在简谐近似和周期性边界条件下,推导考虑所有原子长程库仑作用一维双原子链晶格振动的色散关系.分析讨论长程库仑作用对色散关系的影响,结果表明：随着长程库仑作用的增强,晶格振动模的频率不断减小、色散关系的频隙逐渐变窄直到消失,并且光学支渐渐深陷入声学支中,最终导致光学支在布里渊区中心的最高频率挪到极低频处.

英文摘要：

Under the harmonic approximation of lattice vibration and the periodic boundary condition,the general expression of the dispersion relation of one-dimensional diatomic chain with long-range Coulomb interactions was obtained.The effect of long-range Coulomb interactions on the dispersion relation was analyzed and discussed.The results showed that,with the enhancement of long-range Coulomb interaction,the frequency of vibration modes decreased,the frequency gap of the dispersion relations gradually narrowed till disappeared,and the optical branch gradually got into the acoustics branch,further the maximum frequency of optical branch in the Brillouin zone center moved to extremely low frequency.