标题： 基于第一性原理的多体研究，CsK2Sb的电子和光学性质，一种用于超亮电子源的半导体材料 显示英文标题

标题： First-principles many-body study of the electronic and optical properties of CsK2Sb, a semiconducting material for ultra-bright electron sources

摘要： 我们对CsK2Sb的电子和光学性质进行了全面的第一性原理研究，这是一种用于粒子加速器超亮电子源的半导体材料。 我们的研究基于密度泛函理论和多体微扰理论，提供了建模该材料作为光电阴极的所有要素，包括带隙、能带色散和光学吸收。 在平均场图像之外准确描述这些性质对于考虑多体效应是相关的。 我们在当前最先进的粒子加速器电子源的背景下讨论我们的结果，为改进量子效率、本征发射度和其他决定超亮束光电阴极宏观特性的相关量的建模奠定基础。 显示英文摘要

摘要： We present a comprehensive first-principles investigation of the electronic and optical properties of CsK2Sb, a semiconducting material for ultra-bright electron sources for particle accelerators. Our study, based on density-fuctional theory and many-body perturbation theory, provides all the ingredients to model the emission of this material as a photocathode, including band gap, band dispersion, and optical absorption. An accurate description of these properties beyond the mean-field picture is relevant to take into account many-body effects. We discuss our results in the context of state-of-the-art electron sources for particle accelerators to set the stage towards improved modeling of quantum efficiency, intrinsic emittance, and other relevant quantities determining the macroscopic characteristics of photocathodes for ultra-bright beams.