Dresden 2026 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 46: Ultra-fast Phenomena II

HL 46.5: Talk

Thursday, March 12, 2026, 16:30–16:45, POT/0051

Ab initio Theory of Coherent Phonon Damping in Semimetals — •Yiming Pan and Fabio Caruso — Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität zu Kiel, 24118 Kiel, Germany

Coherent phonon plays an important role in the structural properties of the crystal lattice and ultrafast light-induced phase transition. Following its excitation, atoms oscillate coherently along the excited modes with decaying amplitudes. This dynamical process is commonly modeled with damping oscillators with phenomelogical damping rates. In this work, we derive this model by employing quantum kinetic equations [1], and attribute the damping rate and frequency renormalization of coherent phonon to the imaginary and real parts of the phonon self-energy. To valdiate our approach, we perform first-principles calculation of the damping rate of A_1g phonon arising from electron-phonon coupling and phonon-phonon coupling in semimetals Bi and Sb. The numerical results agree with available temperature- and fluence-dependent experimental data, thereby providing a predictive framework for determining the timescales of structural dynamics in driven solids.

[1] Y. Pan et al., arXiv:2502.01529

Keywords: Coherent phonons; Electron-phonon coupling; Phonon decoherence; Ultrafast electron-phonon dynamics