近日，挪威奥斯陆城市大学的Sølve Selstø及其研究团队取得一项新进展。他们对非相对论狄拉克方程在高荷电类氢离子光离中的应用进行了研究。相关研究成果已于2024年12月26日在国际知名学术期刊《物理评论A》上发表。

该研究团队研究了相对论在激光脉冲光电离类氢离子过程中所起的作用。对于氢原子而言，激光的波长位于弱紫外线区域。对于核电荷数较高的离子，激光参数按一定比例缩放，使得在电偶极近似下的含时薛定谔方程与核电荷数无关。

这些高电荷离子的电离势因相对论效应而发生显著变化。在伊万诺娃等人早先的工作[《物理评论A》98, 063402 (2018)]中，展示了这如何解释了电离概率的大部分相对论修正。

本文研究了剩余差异在多大程度上，可以归因于强外场引起的相对论效应。为此，研究人员求解了薛定谔方程和狄拉克方程的半相对论形式，前者考虑了外激光场引起的惯性增加，而后者则包含了一个非相对论相互作用项。

附：英文原文

Title: Nonrelativistic Dirac equation: An application to photoionization of highly charged hydrogenlike ions

Author: Tor Kjellsson Lindblom, Simen Bræck, and Sølve Selstø*

Issue&Volume: 2024-12-26

Abstract: We investigate the role of relativity in photoionization of hydrogenlike ions by a laser pulse. For hydrogen, the wavelengths of the laser resides in the weakly ultraviolet region. For higher nuclear charges, the laser parameters are scaled in a manner which renders the time-dependent Schrdinger equation in the electric dipole approximation independent of nuclear charge. The ionization potentials of these highly charged ions are strongly modified by relativistic effects. In an earlier work by Ivanova et al. [Phys. Rev. A 98, 063402 (2018)], it is demonstrated how this explains most of the relativistic correction to the ionization probability. Here we investigate to what extent remaining discrepancies can be attributed to relativistic effects stemming from the strong external field. To this end, we solve semirelativistic formulations of both the Schrdinger and the Dirac equations; the former accounts for increased inertia due to the external laser field, while the latter features a nonrelativistic interaction term.

DOI: https://doi.org/10.1103/PhysRevA.110.063120

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.063120