Bethe-Salpeter框架中动力学屏蔽的效应：晶体萘中的激子
Effect of dynamical screening in the Bethe-Salpeter framework: Excitons in crystalline naphthalene
AI总结：
本文在Bethe-Salpeter框架中引入动力学屏蔽效应，以萘晶体为例比较两种近似与精确对角化方法，发现动力学修正约占激子结合能15%，并提出有效屏蔽模型以高效近似复杂材料中的动力学效应。
摘要：
求解光学极化函数的Bethe-Salpeter方程（BSE）是从第一性原理模拟材料光学性质（包括激子效应）的一种方法。一个几乎普遍使用的近似忽略了屏蔽电子-空穴相互作用的频率依赖性。这通常由电子等离子体频率与激子结合能在数值上的巨大差异来证明。我们使用两种不同的近似以及激子哈密顿量的精确对角化，将动力学效应纳入BSE中电子-空穴相互作用的屏蔽。我们在萘有机晶体上比较了这些方法，对于该晶体，激子结合能与等离子体频率之间的差异仅为约十倍。我们的结果表明，在这种情况下，由动力学屏蔽引起的修正约为激子结合能的15%。我们分析了屏蔽动力学对可见光谱范围内光吸收的影响，并利用我们的数据建立了一个有效屏蔽模型，作为未来在复杂材料中近似动力学效应的一种计算高效方法。
英文摘要：
Solving the Bethe-Salpeter equation (BSE) for the optical polarization functions is a first principles means to model optical properties of materials including excitonic effects. One almost ubiquitously used approximation neglects the frequency dependence of the screened electron-hole interaction. This is commonly justified by the large difference in magnitude of electronic plasma frequency and exciton binding energy. We incorporated dynamical effects into the screening of the electron-hole interaction in the BSE using two different approximations as well as exact diagonalization of the exciton Hamiltonian. We compare these approaches for a naphthalene organic crystal, for which the difference between exciton binding energy and plasma frequency is only about a factor of ten. Our results show that in this case, corrections due to dynamical screening are about 15\,\% of the exciton binding energy. We analyze the effect of screening dynamics on optical absorption across the visible spectral range and use our data to establish an \emph{effective} screening model as a computationally efficient approach to approximate dynamical effects in complex materials in the future.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
