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O: Fachverband Oberflächenphysik

O 99: Ultrafast Electron Dynamics IV

O 99.5: Vortrag

Freitag, 21. März 2025, 11:30–11:45, H11

Coherent phonons and quasiparticle renormalization in semimetals from first principles — •Christoph Emeis, Stephan Jauernik, Sunil Dahiya, Yiming Pan, Carl E. Jensen, Petra Hein, Michael Bauer, and Fabio Caruso — Kiel University, Germany

Coherent phonons offer a powerful means to manipulate structural and electronic properties of materials on ultrafast timescales, making them a key tool for exploring light-induced phase transitions and non-equilibrium dynamical phenomena.

We present an ab initio theory for the displacive excitation of coherent phonons in semimetals. We formulate a computational workflow for modelling light-induced structural changes and the resulting transient band-structure renormalization following excitation with a femtosecond laser. This framework is based on first-principles simulations of ultrafast electron and coherent phonon dynamics in the presence of electron-phonon interactions. We validate our approach through a combined theoretical and experimental study of coherent phonons in the semimetal antimony. The robust agreement between photoemission experiments and simulations corroborates our approach and paves the way for new opportunities to control structural and electronic degrees of freedom in semimetals via coherent phonon excitation.

C. Emeis et al. arXiv:2407.17118

Keywords: Electron-phonon interaction; Displacive excitation of coherent phonons; Ultrafast electron-phonon dynamics; ab initio method; ARPES