Ga和Sb纳米线声子结构和电子-声子相互作用的第一性原理研究

基于密度泛函理论的第一性原理方法,系统研究了Ga和Sb纳米线的电子能带结构和声子结构以及电子-声子耦合(EPC)作用.通过对声子的完整Brillouin区分析来研究纳米线的结构稳定性.结果表明,所考察的纳米线显示出不稳定性,不稳定声子波矢远离Brillouin区中心.与通常的Peierls变形机理相比,不稳定的横向声子模会导致一种无开口带隙的相变.Sb比Ga纳米线的EPC要强很多,并且横向变形导致的锯齿形结构使纳米线中的电子-声子相互作用增加了几个数量级.

Phonon band structure and electron-phonon interactions in Ga and Sb nanowires: a first-principles study

We present first-principles calculations of the electronic and phonon band structure considering electron-phonon coupling in thin Ga and Sb nanowires. A full Brillouin zone analysis of the phonons is performed for the investigation of nanowire structural stability. The examined nanowires show instability while the wave vectors are away from the zone center. Compared with the usual Peierls distortion picture, the unstable transverse phonon modes induce a transition without electronic band-gap opening. Electron-phonon interaction yields orders-of-magnitude changes depending on the nanowire structure.