论文标题
$ GW $方法中的非物理不连续性，入侵者状态和正规化
Unphysical Discontinuities, Intruder States and Regularization in $GW$ Methods
论文作者
论文摘要
通过将非线性频率依赖性$ GW $ Quasiparticle方程重新铸造到线性特征值问题中，我们解释了在$ GW $近似中计算的各种物理数量中多种解决方案和非物理不合时间的外观。考虑到$ gw $自我能源作为有效的哈密顿量，这表明这些问题是$（n \ pm1）$ - 电子状态的密切相关性的关键签名，并且可以与入侵者状态问题直接相关。提出了一个受相似性重量化组启发的简单有效的正则化程序，以避免此类问题并加快部分自洽$ GW $计算的收敛性。
By recasting the non-linear frequency-dependent $GW$ quasiparticle equation into a linear eigenvalue problem, we explain the appearance of multiple solutions and unphysical discontinuities in various physical quantities computed within the $GW$ approximation. Considering the $GW$ self-energy as an effective Hamiltonian, it is shown that these issues are key signatures of strong correlation in the $(N\pm1)$-electron states and can be directly related to the intruder state problem. A simple and efficient regularization procedure inspired by the similarity renormalization group is proposed to avoid such issues and speed up convergence of partially self-consistent $GW$ calculations.
