Last Monday, November 23rd, ICREA professor at ICFO Jens Biegert gave a seminar at the Fritz-Haber Institut of the Max Planck Gesellschaft.

The Physical Chemistry Department organized the seminar, titled “Energy Conversion Pathways in Graphite from Attosecond Soft X-ray Spectroscopy,” and streamed it through Zoom

Abstract of the talk

The build-up of electronic coherences and their subsequent dephasing into excited quasiparticles due to scattering processes, occurring on atto- and femtosecond timescales, govern the conversion of light to fundamental excitations of matter. Disentangling the interplay of these mechanisms, and how they lead to a specific flow of energy inside a material, is extremely challenging since many of these effects occur on overlapping temporal scales. I will discuss how we investigated the semimetal graphite with attosecond K-shell X-ray absorption near edge structure (XANES) spectroscopy and show how the combination of our new measurement methodology with theoretical modelling allows us to assign the spectroscopic signatures to microscopic processes relating to the dynamic evolution of electrons, holes and phonon modes of the material.

Lastly, since this new method is generally applicable to molecules and solids, I will point out some possibilities to address canonical questions relevant for light-harvesting and general non-equilibrium multi-body physics of phase-transitions.