标题： 双圆高次谐波光谱中的电子结构特征 显示英文标题

标题： Signatures of electronic structure in bi-circular high-harmonic spectroscopy

摘要： 由圆偏振激光脉冲驱动的高次谐波光谱及其相反旋转的二次谐波是阿秒科学的一个新分支，目前尚缺乏定量解释。 我们将该技术扩展到中红外区域，并记录了多种稀有气体原子的详细高次谐波光谱。 这些结果与三维薛定谔方程的解以及基于强场近似且包含精确散射波再结合矩阵元的计算进行了比较。 对这些结果的量子轨道分析提供了对测量的对称性允许的相邻谐波强度比的清晰解释，这涉及（i）与原子轨道角动量相关的倾向性规则，（ii）与它们电子结构相关的原子特异性矩阵元，以及（iii）与在与激光场共旋或反旋轨道中的电子相关的发射的干涉。 这些结果为对双圆偏振高次谐波光谱的定量理解奠定了基础。 显示英文摘要

摘要： High-harmonic spectroscopy driven by circularly-polarized laser pulses and their counter-rotating second harmonic is a new branch of attosecond science which currently lacks quantitative interpretations. We extend this technique to the mid-infrared regime and record detailed high-harmonic spectra of several rare-gas atoms. These results are compared with the solution of the Schrodinger equation in three dimensions and calculations based on the strong-field approximation that incorporate accurate scattering-wave recombination matrix elements. A quantum-orbit analysis of these results provides a transparent interpretation of the measured intensity ratios of symmetry-allowed neighboring harmonics in terms of (i) a set of propensity rules related to the angular momentum of the atomic orbitals, (ii) atom-specific matrix elements related to their electronic structure and (iii) the interference of the emissions associated with electrons in orbitals co- or counter-rotating with the laser fields. These results provide the foundation for a quantitative understanding of bi-circular high-harmonic spectroscopy.