多散射理论框架下同核双原子分子中zepto到阿秒量级的芯能级光发射时间延迟及非偶极效应
Zepto to Attosecond core-level photoemission time delays in homonuclear diatomic molecules and non-dipole effects in the framework of Multiple Scattering theory
AI总结：
本研究理论探究同核双原子分子芯能级光发射时间延迟角分布，聚焦非偶极效应致对称性破缺，基于多散射理论建模揭示双中心干涉抵消及残余非偶极效应，应用于氮分子验证并展示其能量角度依赖特性。
摘要：
本研究从理论上探究了分子框架内芯能级光发射时间延迟的角分布，该现象可借助阿秒脉冲激光及计量技术的进步进行测量。我们聚焦于同核双原子分子，其gerade和ungerade芯能级分子框架光电子角分布（MFPAD）中观察到的双中心干涉图样，显示出相对于光传播方向的对称性破缺，这归因于非偶极（多极）效应。本研究通过引入理论模型深入探讨了非偶极效应导致的光发射时间延迟，揭示了当考虑gerade和ungerade离域态的非相干和时，双中心干涉项在MFPAD和光发射时间延迟中均相互抵消，但仍存在残余项，体现了光发射时间延迟中的非偶极效应。此外，通过利用多散射理论展开光电子的散射态，我们证明了光电子在分子势场中的散射在描述同核双原子分子光发射时间延迟时的重要作用。随后，我们将理论模型应用于氮分子，通过解析和数值方法展示了MFPAD及光发射时间延迟的能量和角度依赖特性；前向和后向MFPAD的非相干和强度相等，而光发射时间延迟的非相干和与多散射代码数值计算结果相比，显示出几百zeptosecond的微小变化。
英文摘要：
This study theoretically investigates the angular distribution of core-level photoemission time delay within a molecular frame. This phenomenon can be measured with the advancement of attosecond pulsed lasers and metrology. Our focus is on homonuclear diatomic molecules. The two-center interference patterns observed in the gerade and ungerade core-level Molecular-Frame Photoelectron Angular Distributions (MFPAD) of homonuclear diatomic molecules demonstrate symmetry breaking with respect to the direction of light propagation, attributed to the non-dipole (multipole) effect. Our study delves into the photoemission time delay resulting from the non-dipole effect through the introduction of a theoretical model. We reveal that when considering the contributions from the gerade and ungerade delocalized states in incoherent sums, the two-center interference terms cancel each other in both the MFPADs and photoemission time delays. However, a residual term persists showcasing the non-dipole effect in the photoemission time delays. Furthermore, by expanding the scattering state of photoelectrons using the Multiple Scattering theory, we demonstrate the significant role played by the scattering of photoelectrons at the molecular potential in describing the photoemission time delays of homonuclear diatomic molecules. Next, we apply our theoretical model to a nitrogen molecule, demonstrating the energy- and angular-dependent characteristics of the MFPADs and photoemission time delays through both analytical and numerical approaches. The incoherent sums of the MFPADs in both forward and backward directions exhibit equal intensity, whereas the incoherent sums of the photoemission time delays show a slight variation of a few hundred zeptoseconds compared with numerical calculations using a multiple scattering code.
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。
