Analytic modeling of structures in attosecond transient-absorption spectra

作者:Rorstad Jorgen Johansen*; Baekhoj Jens E; Madsen Lars Bojer
来源:PHYSICAL REVIEW A, 2017, 96(1): 013430.
DOI:10.1103/PhysRevA.96.013430

摘要

Attosecond transient-absorption spectroscopy (ATAS) is an established method for exploring electron dynamics on the subfemtosecond time scale. ATAS spectra contain certain ubiquitous features, such as oscillating fringes, light-induced structures, and hyperbolic sidebands, representing physical processes. We derive closed analytical expressions describing these features, based on a three-level system responding adiabatically to the influence of an infrared field in conjunction with an extreme ultraviolet pulse, and use He to illustrate the theory. The validity of the formulas is substantiated by comparing their predictions with spectra calculated numerically by the time-dependent Schrodinger equation. The closed analytical forms and the details of their derivation resolve the origins of the features.

  • 出版日期2017-7-28