论文标题
测量具有attosecond noncolrinear四波混合光谱的霓虹子原子中光学上禁止内价激发态的自动离子衰减寿命
Measuring autoionization decay lifetimes of optically forbidden inner valence excited states in neon atoms with attosecond noncollinear four wave mixing spectroscopy
论文作者
论文摘要
使用一个Attosond极端紫外线（XUV）脉冲和两个几个周期的近红外（NIR）脉冲来测量NEON原子中内价电子激发的自由离子衰减寿命。在43-48 EV XUV光子中，将2S电子激发到2S2P6 [NP] Rydberg系列中，宽带NIR脉冲将2S2P6 [3P] XUV-Bright状态与相邻的2S2P6 [3S] [3S]和2S2P6 [3D] [3D] Xuv-dark State。相对于Attosecond Xuv脉冲的一个或两种NIR脉冲的可控延迟分别揭示了黑暗或明亮状态的时间演化。 3S，3P和3D状态的实验寿命分别为7 +/- 2 FS，48 +/- 8 FS和427 +/- 40 FS，置信度为95％。伴随两种独立的AB从头算理论方法Newstock和Astra的计算验证了这些发现。结果支持预期的趋势，即在2S核心孔的径向区域中渗透较小的州应更长的寿命，在这种情况下，这是针对较高的角动量Rydberg轨道的。因此，基本理论将生命周期的结果与电子相关性联系起来，并评估自动化过程中的直接和交换项。
Attosecond noncollinear four wave mixing spectroscopy with one attosecond extreme ultraviolet (XUV) pulse and two few-cycle near-infrared (NIR) pulses was used to measure the autoionization decay lifetimes of inner valence electronic excitations in neon atoms. After a 43-48 eV XUV photon excites a 2s electron into the 2s2p6[np] Rydberg series, broadband NIR pulses couple the 2s2p6[3p] XUV-bright state to neighboring 2s2p6[3s] and 2s2p6[3d] XUV-dark states. Controllable delays of one or both NIR pulses with respect to the attosecond XUV pulse reveal the temporal evolution of either the dark or bright states, respectively. Experimental lifetimes for the 3s, 3p, and 3d states are measured to be 7 +/- 2 fs, 48 +/- 8 fs, and 427 +/- 40 fs, respectively, with 95% confidence. Accompanying calculations with two independent ab initio theoretical methods, NewStock and ASTRA, verify the findings. The results support the expected trend that the autoionization lifetime should be longer for states that have a smaller penetration in the radial region of the 2s core hole, which in this case is for the higher angular momentum Rydberg orbitals. The underlying theory thus links the lifetime results to electron correlation and provides an assessment of the direct and exchange terms in the autoionization process.
