ABSTRACT The internuclear distance (R) dependence of the correlated electron dynamics in strong-field nonsequential double ionization (NSDI) of parallel aligned diatomic molecules has been investigated. Results show the correlated electron momentum distribution (CEMD) is almost uniformly spread in the four quadrants for R = 4 a.u., while for larger R it is mainly located in the first and third quadrants. Classifying NSDI events into recollision and internal-collision processes demonstrates the CEMD of internal-collision induced NSDI is strongly dependent on R, which changes from a uniform distribution to a back-to-back emission pattern, and finally to a side-by-side emission pattern as R increases. Back analyzing of the classical trajectories shows it originates from the R dependent time delay between double ionization and collision times. When R increases, more and more internal-collision induced NSDI events occur immediately after collision, resulting in the enhanced dominance of the electron emission in the same hemisphere.

中文翻译：

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内碰撞诱导分子非序列双电离的核间距离依赖性

摘要 研究了平行排列的双原子分子的强场非连续双电离 (NSDI) 中相关电子动力学的核间距离 (R) 依赖性。结果表明，对于 R = 4 au，相关电子动量分布 (CEMD) 在四个象限中几乎均匀分布，而对于较大的 R，它主要位于第一和第三象限。将 NSDI 事件分为再碰撞和内部碰撞过程表明内部碰撞引起的 NSDI 的 CEMD 强烈依赖于 R，从均匀分布变为背靠背发射模式，最后变为并排随着 R 增加的发射模式。经典轨迹的回溯分析表明它源于双电离和碰撞时间之间的 R 相关时间延迟。