超晶格基元的声子结构

Study on Phonon Structure in Unit Cell of Superlattice

应用Dyson方程推导了超晶格基元的声子格林函数,并以此为基础研究了超晶格基元的声子结构.计算结果表明,由于表面与界面效应,在超晶格基元中,声子能带分裂为一系列微带,在界面耦合力常数较大时,还出现了界面局域声子模.

The phonon Green's function of unit cell in superlattice is deduced with Dyson's equation, on the basis of this result, the phonon structure in unit cell of superlattice is studied. It is found that because of the surface and interface effects, the energy band of phonon splits into a series of minibands, and localized phonon appears near interface when the couple force constant is large enough.