Coupled nuclear-electronic decay dynamics of O2 inner valence excited states revealed by attosecond XUV wave-mixing spectroscopy.
Coupled nuclear-electronic decay dynamics of O2 inner valence excited states revealed by attosecond XUV wave-mixing spectroscopy.
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阿秒 XUV 波混合光谱揭示 O2 内价激发态的耦合核电子衰变动力学。
DOI：
10.26434/chemrxiv.13079750.v1
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发表时间：
2020
影响因子：
3.4
通讯作者：
D. Neumark
中科院分区：
文献类型：
--
作者：
Yen;A. Fidler;A. Sandhu;R. Lucchese;C.;William McCurdy;S. Leone;D. Neumark
通过 20-25 eV 极紫外 (XUV) 光照射，收敛到 O2+ c 4Σ-u 态的多个里德伯级数是核解离和电子自电离之间竞争的重要模型系统。这些系列中最低成员（21 eV 左右的 3sσg 态）的动力学由于其超短寿命（<10 fs）而一直难以研究。在这里，我们应用瞬态波混合光谱和阿秒 XUV 脉冲来研究这种电子态的衰变动力学。对于 3s 里德堡态的 v = 0 和 v = 1 振动能级，分别获得 95% 置信区间下的 5.8 ± 0.5 fs 和 4.5 ± 0.7 fs 的寿命。对预解离和电子自电离的理论处理发现，这些寿命由电子自电离主导。由于穿过 3s 里德伯态的两个离子衰变通道，电子自电离速率对核间距离的强烈依赖性导致两个振动能级的寿命不同。计算出的寿命对于 3s 电势相对于衰变通道的位置高度敏感；通过稍微调整位置，计算得出 v = 0 和 v = 1 水平的值分别为 6.2 和 5.0 fs，与实验非常吻合。总体而言，阿秒 XUV 波混合光谱揭示了耦合核电子动力学的有趣图像，表明衰变动力学并不是孤立的自电离和预解离过程之间的简单竞争。
Multiple Rydberg series converging to the O2+ c 4Σ-u state, accessed by 20-25 eV extreme ultraviolet (XUV) light, serve as important model systems for the competition between nuclear dissociation and electronic autoionization. The dynamics of the lowest member of these series, the 3sσg state around 21 eV, has been challenging to study owing to its ultra-short lifetime (<10 fs). Here, we apply transient wave-mixing spectroscopy with an attosecond XUV pulse to investigate the decay dynamics of this electronic state. Lifetimes of 5.8 ± 0.5 fs and 4.5 ± 0.7 fs at 95% confidence intervals are obtained for v = 0 and v = 1 vibrational levels of the 3s Rydberg state, respectively. A theoretical treatment of predissociation and electronic autoionization finds that these lifetimes are dominated by electronic autoionization. The strong dependence of the electronic autoionization rate on the internuclear distance because of two ionic decay channels that cross the 3s Rydberg state results in the different lifetimes of the two vibrational levels. The calculated lifetimes are highly sensitive to the location of the 3s potential with respect to the decay channels; by slight adjustment of the location, values of 6.2 and 5.0 fs are obtained computationally for the v = 0 and v = 1 levels, respectively, in good agreement with experiment. Overall, an intriguing picture of the coupled nuclear-electronic dynamics is revealed by attosecond XUV wave-mixing spectroscopy, indicating that the decay dynamics are not a simple competition between isolated autoionization and predissociation processes.
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影响因子：
56.9
作者：
Kobayashi, Yuki;Chang, Kristina F.;Leone, Stephen R.
通讯作者：
Leone, Stephen R.
影响因子：
16.6
作者：
Marroux HJB;Fidler AP;Ghosh A;Kobayashi Y;Gokhberg K;Kuleff AI;Leone SR;Neumark DM
通讯作者：
Neumark DM
影响因子：
2.9
作者：
A. Plunkett;N. Harkema;R. Lucchese;C. W. McCurdy;A. Sandhu
通讯作者：
A. Plunkett;N. Harkema;R. Lucchese;C. W. McCurdy;A. Sandhu
影响因子：
56.9
作者：
Ott, Christian;Kaldun, Andreas;Pfeifer, Thomas
通讯作者：
Pfeifer, Thomas