Speaker
Description
Ultrashort extreme-ultraviolet (XUV) pulses from high-harmonic generation (HHG) are a powerful tool for novel experiments in the area of ultrafast surface science. The short-wavelength nature of these sources provide important information related to all electronic, magnetic, structural, and chemical properties of a solid. In the beginning of my talk, I will exemplarily introduce a set of surface science experiments, where the usage of XUV light from HHG did considerably help to answer some of the key questions in the respective research field [e.g. 1,2]. I will further discuss current developments in HHG-based photoelectron spectroscopy, and show that it is now possible to map spin-dependent band structure dynamics using this technique. Here, we did study the response in Co to an ultrafast photo-induced spin current [3]. Via mapping of the spin-resolved band-structure dynamics, we find that optically driven femtosecond spin currents induce collective spin excitations on extremely fast timescales.
[1] E. Turgut et al., Phys. Rev. Lett. 110, 107201 (2013)
[2] O. Kfir et al., Science Adv. 3, eaao4641 (2017)
[3] S. Eich et al., Science Adv. 3, e1602094 (2017)
