Attosecond x-ray transient absorption in condensed-matter: a core-state-resolved Bloch model. (15th April 2019)

• Record Type: Journal Article
• Authors: Picón, A; Plaja, L; Biegert, J
• Is Part Of: New journal of physics. Volume 21:Number 4(2019:Apr.)
• Publication Date: 2019-04-15
• Subjects: attosecond transient absorption -- ultrafast x-ray spectroscopy -- semiconductor and two-dimensional materials; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/ab1311
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: Attosecond transient absorption is an ultrafast technique that has opened the possibility to study electron dynamics in condensed matter systems at its natural timescale. The extension to the x-ray regime permits one to use this powerful technique in combination with the characteristic element specificity of x-ray spectroscopy. At these timescales, the coherent effects of the electron transport are essential and have a relevant signature on the absorption spectrum. Typically, the complex light-driven dynamics requires a theoretical modeling for shedding light on the time-dependent changes in the spectrum. Here we construct a semiconductor Bloch equation model for resolving the light-induced and core-electron dynamics simultaneously, which enables to easily disentangle the interband and intraband contributions. By using the Bloch model, we demonstrate a universal feature on attosecond x-ray transient absorption spectra that emerges from the light-induced coherent intraband dynamics. This feature is linked to previous studies of light-induced Fano resonances in atomic systems.