Enhanced one-photon double ionization of atoms and molecules in an environment of different species.
Enhanced one-photon double ionization of atoms and molecules in an environment of different species.
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增强不同物种环境中原子和分子的单光子双电离。
DOI：
10.1103/physrevlett.112.193001
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发表时间：
2014
影响因子：
8.6
通讯作者：
L. Cederbaum
中科院分区：
文献类型：
--
作者：
V. Stumpf;N. Kryzhevoi;K. Gokhberg;L. Cederbaum
原子和分子中电子态的相关性质表现为在吸收接近各自阈值的单个光子后同时发射两个电子。对原子和小分子的大量观察表明，接近阈值的双电离效率相当小。在这封信中，我们表明这种效率可以在环境中得到显着提高。具体来说，我们关注的是所讨论的物种有一个或多个 He 原子作为邻居的情况。这种增强是通过间接过程实现的，其中环境中的 He 原子吸收光子，产生的 He(+) 阳离子通过称为电子转移介导衰变的过程快速中和，从而产生双电离物质。以 Mg·He 团簇为例详细证明了双电离的增强。我们发现 Mg 的双电离截面比孤立 Mg 原子的相应截面大 3 个数量级。讨论了更多邻居的影响，并解决了对其他物种和环境的影响。
The correlated nature of electronic states in atoms and molecules is manifested in the simultaneous emission of two electrons after absorption of a single photon close to the respective threshold. Numerous observations in atoms and small molecules demonstrate that the double ionization efficiency close to threshold is rather small. In this Letter we show that this efficiency can be dramatically enhanced in the environment. To be specific, we concentrate on the case where the species in question has one or several He atoms as neighbors. The enhancement is achieved by an indirect process, where a He atom of the environment absorbs a photon and the resulting He(+) cation is neutralized fast by a process known as electron transfer mediated decay, producing thereby doubly ionized species. The enhancement of the double ionization is demonstrated in detail for the example of the Mg · He cluster. We show that the double ionization cross section of Mg becomes 3 orders of magnitude larger than the respective cross section of the isolated Mg atom. The impact of more neighbors is discussed and the extension to other species and environments is addressed.