Coulomb excitations in AA- and AB-stacked bilayer graphites
Coulomb excitations in AA- and AB-stacked bilayer graphites
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DOI：
10.1103/physrevb.74.085406
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发表时间：
2006-08-01
影响因子：
3.7
通讯作者：
Lin, M. F.
中科院分区：
文献类型：
--
作者：
Ho, J. H.;Lu, C. L.;Lin, M. F.
用线性自洽场方法研究了AA和AB双层石墨的π电子激发。它们强烈地受到堆叠顺序、层间原子相互作用、层间库仑相互作用和转移动量的大小的影响。然而，它们几乎不依赖于传递动量的方向和温度。在AA堆叠系统中存在三种低频等离子体激元模，而在AB堆叠系统中没有。AA-和AB-堆叠的等离子体表现出类似的pi等离子体。第一个低频等离子体激元表现为声学等离子体激元，其他的属于光学等离子体激元。双层石墨与单层石墨和AB-堆积体石墨有很大的不同，如低频等离子体激元和小动量π等离子体激元。
The pi-electronic excitations are studied for the AA- and AB-stacked bilayer graphites within the linear self-consistent-field approach. They are strongly affected by the stacking sequence, the interlayer atomic interactions, the interlayer Coulomb interactions, and the magnitude of the transferred momentum. However, they hardly depend on the direction of the transferred momentum and the temperature. There are three low-frequency plasmon modes in the AA-stacked system but not the AB-stacked system. The AA- and AB-stacked plasmons exhibit the similar pi plasmons. The first low-frequency plasmon behaves as an acoustic plasmon, and the others belong to optical plasmons. The bilayer graphites quite differ from the monolayer graphite and the AB-stacked bulk graphite, such as the low-frequency plasmons and the small-momentum pi plasmons.