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O: Fachverband Oberflächenphysik
O 48: Poster Surface Dynamics
O 48.1: Poster
Dienstag, 18. März 2025, 18:00–20:00, P2
Atomistic modeling of ultrafast laser induced structural changes in Bismuth — •Sahar Bakhshi Sangari, Jimiben Patel, Bernd Bauerhenne, and Martin Garcia — Institute of Physics, University of Kassel, Kassel, Germany
We present a temperature-dependent interatomic potential for laser-excited bismuth, ΦBi(Te), developed using a database of temperature-dependent density functional theory (DFT) calculations. Bismuth is a widely studied material in experiments, yet theoretical studies exploring its atomic dynamics following femtosecond laser excitation remain scarce. Our work compares the physical properties predicted by ΦBi(Te) with those obtained from ab initio simulations, demonstrating its reliability. We use ΦBi(Te) to describe, in the framework of a generalized two-temperature-model molecular dynamics (TTM-MD) method, laser induced thermal and nonthermal ultrafast structural changes in Bi. We compute the time evolution of selected Bragg peaks and directly compare them with experimental observations. This approach enables efficient and accurate modeling of complex material behaviors, providing a valuable alternative to computationally intensive temperature-dependent DFT simulations.
Keywords: Ultrafast structural dynamics; Two-temperature model (TTM-MD); Density functional theory (DFT); Temperature-dependent interatomic potential; Laser-excited bismuth