Atomic displacement Induced by Core Excitation and its Spectral Theory

(1)石墨芯激子的共振X射线发射光谱表现出明显的低能尾和偏振依赖性。在共振二阶光学过程理论中，我们用团簇振动模型对实验数据进行了分析。结果表明，在芯空穴寿命内，核激发的碳原子发生了对称性破缺原子位移。(2)考虑了强振动相互作用、电子巡游效应和现场库仑排斥作用，研究了芯孔俄歇衰变引起的表面离子脱附的机理。设计了一种用于全量子力学计算的数值模拟技术。结果表明，Coulomb排斥对稳定双空穴局域态，从而提高原子位移效率起着至关重要的作用。(3)利用最外层核心区空穴的自陷模型，解释了CsClUV-Auger自由发射光谱中双峰结构的来源及其特殊的温度关系。提出了一种扩展的可变形团簇模型来计算发射光谱。(4)提出了一种新的激子波包动力学的超快光谱技术。

(1)The resonant X-ray emission spectrum of core excitons in graphite shows an eminent low energy tails and polarization dependence. We have analyzed the experimental data by a cluster-vibronic model within the theory of resonant second orderoptical process. It has been shown that a symmetry breaking atomic displacement of the core-excited carbon atom occurs within the lifetime of the is core hole.(2)The mechanism of ionic desorption from surfaces induced by the Auger decay of core holes is investigated by taking into account the strong vibronic interaction, the effect of electron itineracy and the on-site Coulomb repulsion. A numerical simulation technique has been devised for a full quantum mechanical calculation. It has been made clear that the on-site Coulomb repulsion takes an essential role to stabilize the two-hole localized state, thus enhancing the efficiency of atomic displacement.(3)The origin of the two-peak structure in the UV Auger-free emission spectrum of CsCl and its peculiar temperature dependence have been clarified by a self-trapping model of the core hole in the outermost core band. An extended deformable cluster model has been proposed to calculate the emission spectra.(4)We proposed a new technique of ultrafast spectroscopy for the wave packet dynamics of excitons.