He Pei-Lun, Hatsagortsyan Karen Z, Keitel Christoph H
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
Phys Rev Lett. 2022 May 6;128(18):183201. doi: 10.1103/PhysRevLett.128.183201.
Recently two-center interference in single-photon molecular ionization was employed to observe a zeptosecond time delay due to the photon propagation of the internuclear distance in a molecule [Grundmann et al., Science 370, 339 (2020)SCIEAS0036-807510.1126/science.abb9318]. We investigate the possibility of a comparable nondipole time delay in tunneling ionization and decode the emerged time delay signal. With the here newly developed Coulomb-corrected nondipole molecular strong-field approximation, we derive and analyze the photoelectron momentum distribution, the signature of nondipole effects, and the role of the degeneracy of the molecular orbitals. We show that the ejected electron momentum shifts and interference fringes efficiently imprint both the molecule structure and laser parameters. The corresponding nondipole time delay value significantly deviates from that in single-photon ionization. In particular, when the two-center interference in the molecule is destructive, the time delay is independent of the bond length. We also identify the double-slit interference in tunneling ionization of atoms with nonzero angular momentum via a nondipole momentum shift.
最近，单光子分子电离中的双中心干涉被用于观测由于分子中核间距的光子传播而产生的zeptosecond时间延迟[Grundmann等人，《科学》370, 339 (2020)SCIEAS0036 - 807510.1126/science.abb9318]。我们研究了隧穿电离中可比的非偶极时间延迟的可能性，并解码出现的时间延迟信号。利用这里新开发的库仑校正非偶极分子强场近似，我们推导并分析了光电子动量分布、非偶极效应的特征以及分子轨道简并性的作用。我们表明，出射电子动量的移动和干涉条纹有效地印记了分子结构和激光参数。相应的非偶极时间延迟值与单光子电离中的值有显著偏差。特别是，当分子中的双中心干涉具有破坏性时，时间延迟与键长无关。我们还通过非偶极动量移动识别了具有非零角动量的原子隧穿电离中的双缝干涉。
