A Simplified Method for the Computation of Correlation Effects on the Band Structure of Semiconductors
A Simplified Method for the Computation of Correlation Effects on the Band Structure of Semiconductors
复制标题
计算半导体能带结构相关效应的简化方法
DOI：
10.1007/s00214-006-0091-7
复制
发表时间：
2005
影响因子：
1.7
通讯作者：
H. Stoll
中科院分区：
文献类型：
--
作者：
U. Birkenheuer;P. Fulde;H. Stoll
为了计算电子关联对金刚石和硅能带的影响，我们提出了一个简化的计算方案。通过采用准粒子图像，我们首先计算周围的弛豫和极化效应的电子设置到导带的Wannier轨道。这是通过允许在自洽场（SCF）计算中放松价轨道来完成的。哈密顿量的对角矩阵元素导致导带的重心移动，而非对角矩阵元素导致导电电子带宽的小幅减小。这个计算是补充的计算的基态相关性的损失，由于阻塞的瓦尼尔轨道，其中添加的电子已被放置。相同的程序适用于电子的去除，即，到价带。但后者已经在以前的一些细节计算和以前的结果被用来估计在两种材料的能隙。这里报道的数值数据表明，该方法的作品，在原则上，但一些扩展的计划也是必要的，以获得完全满意的结果。
We present a simplified computational scheme in order to calculate the effects of electron correlations on the energy bands of diamond and silicon. By adopting a quasiparticle picture we compute first the relaxation and polarization effects around an electron set into a conduction-band Wannier orbital. This is done by allowing the valence orbitals to relax within a self-consistent field (SCF) calculation. The diagonal matrix element of the Hamiltonian leads to a shift of the center of gravity of the conduction band while the off-diagonal matrix elements result in a small reduction of the conduction-electron bandwidth. This calculation is supplemented by the computation of the loss of ground-state correlations due to the blocked Wannier orbital into which the added electron has been placed. The same procedure applies to the removal of an electron, i.e., to the valence bands. But the latter have been calculated previously in some detail and previous results are used to estimate the energy gap in the two materials. The numerical data reported here show that the methods works, in principle, but that some extension of the scheme is also necessary to obtain fully satisfactory results.