Kübel M, Spanner M, Dube Z, Naumov A Yu, Chelkowski S, Bandrauk A D, Vrakking M J J, Corkum P B, Villeneuve D M, Staudte A
Joint Attosecond Science Laboratory, National Research Council and University of Ottawa, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada.
Department of Physics, Ludwig-Maximilians-Universität Munich, Am Coulombwall 1, D-85748, Garching, Germany.
Nat Commun. 2020 May 22;11(1):2596. doi: 10.1038/s41467-020-16422-2.
The strong coupling between intense laser fields and valence electrons in molecules causes distortions of the potential energy hypersurfaces which determine the motion of the nuclei and influence possible reaction pathways. The coupling strength varies with the angle between the light electric field and valence orbital, and thereby adds another dimension to the effective molecular potential energy surface, leading to the emergence of light-induced conical intersections. Here, we demonstrate that multiphoton couplings can give rise to complex light-induced potential energy surfaces that govern molecular behavior. In the laser-induced dissociation of H, the simplest of molecules, we measure a strongly modulated angular distribution of protons which has escaped prior observation. Using two-color Floquet theory, we show that the modulations result from ultrafast dynamics on light-induced molecular potentials. These potentials are shaped by the amplitude, duration and phase of the dressing fields, allowing for manipulating the dissociation dynamics of small molecules.
强激光场与分子中的价电子之间的强耦合会导致势能超曲面发生畸变，而势能超曲面决定了原子核的运动并影响可能的反应路径。耦合强度随光电场与价轨道之间的夹角而变化，从而为有效的分子势能面增添了另一个维度，导致光诱导锥形交叉点的出现。在此，我们证明多光子耦合能够产生控制分子行为的复杂光诱导势能面。在最简单的分子——氢分子的激光诱导解离过程中，我们测量到了之前未被观测到的质子角分布的强烈调制。利用双色弗洛凯理论，我们表明这些调制是由光诱导分子势上的超快动力学引起的。这些势由修饰场的振幅、持续时间和相位塑造，从而能够操控小分子的解离动力学。
