Vertex Corrections for Positive-Definite Spectral Functions of Simple Metals.
Vertex Corrections for Positive-Definite Spectral Functions of Simple Metals.
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简单金属正定谱函数的顶点校正
DOI：
10.1103/physrevlett.117.206402
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发表时间：
2016
影响因子：
8.6
通讯作者：
R. van Leeuwen
中科院分区：
文献类型：
--
作者：
Y. Pavlyukh;A.-M. Uimonen;G. Stefanucci;R. van Leeuwen
我们对金属密度下均匀电子气中的顶点校正进行了系统研究。顶点图是使用最近提出的谱函数的正定图解展开来构建的。顶点函数不仅提供了对众所周知的等离子体和粒子空穴散射的校正，而且还产生了新的物理过程，例如产生两个等离子体激发或单粒子态衰变为双粒子单空穴态。通过有效的蒙特卡罗动量积分，我们能够证明额外的散射通道导致带宽减少、费米能级以下二次等离激元卫星的出现以及光谱权重的显着重新分配。还讨论了第一原理能带结构计算方法的可行性。
We present a systematic study of vertex corrections in a homogeneous electron gas at metallic densities. The vertex diagrams are built using a recently proposed positive-definite diagrammatic expansion for the spectral function. The vertex function not only provides corrections to the well known plasmon and particle-hole scatterings, but also gives rise to new physical processes such as the generation of two plasmon excitations or the decay of the one-particle state into a two-particle–one-hole state. By an efficient Monte Carlo momentum integration we are able to show that the additional scattering channels are responsible for a reduction of the bandwidth, the appearance of a secondary plasmon satellite below the Fermi level, and a substantial redistribution of spectral weights. The feasibility of the approach for first-principles band-structure calculations is also discussed.