Ab Initio GW Many-Body Effects in Graphene
Ab Initio GW Many-Body Effects in Graphene
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DOI：
10.1103/physrevlett.101.226405
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发表时间：
2008-11-28
影响因子：
8.6
通讯作者：
Olevano, Valerio
中科院分区：
文献类型：
--
作者：
Trevisanutto, Paolo E.;Giorgetti, Christine;Olevano, Valerio
我们提出了独立式石墨烯能带图的从头算多体引力波数值计算。我们考虑通过包含非厄米和动力学项的自能引入 e-e 相互作用和相关效应的完整离子和电子结构。相对于密度泛函理论局域密度近似，费米速度进行了重正化，增加了17%，与实验结果更加吻合。通过角分辨光电子能谱观察到，接近狄拉克点时，线性色散因扭结的存在而发生改变。我们证明了扭结是由于低能 pi ->pi(*) 单粒子激发和 pi 等离子体引起的。引力波自能不会打开带隙。
We present an ab initio numerical many-body GW calculation of the band plot in freestanding graphene. We consider the full ionic and electronic structure introducing e-e interaction and correlation effects via a self-energy containing non-Hermitian and dynamical terms. With respect to the density-functional theory local-density approximation, the Fermi velocity is renormalized with an increase of 17%, in better agreement with the experiment. Close to the Dirac point the linear dispersion is modified by the presence of a kink, as observed by angle-resolved photoemission spectroscopy. We demonstrate that the kink is due to low-energy pi ->pi(*) single-particle excitations and to the pi plasmon. The GW self-energy does not open the band gap.