Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 72: Graphene: Theory (jointly with DS, HL, MA, and TT)

O 72.4: Vortrag

Donnerstag, 14. März 2013, 15:45–16:00, H17

Lattice dynamics of few-layer graphene after ultrashort laser excitation — •Naira Grigoryan, Eeuwe S. Zijlstra, and Martin E. Garcia — Universität Kassel, Kassel, Germany

Femtosecond laser pulses may induce striking structural effects in solids via electronic excitation. Here we studied the phonon dynamics on the 10 ps timescale in thin graphite films as a function of its thickness after laser interaction using ab initio molecular dynamics simulations including a Van der Waals force correction term to the local density approximation. We implemented the coupling of the hot electrons with the so- called strongly coupled optical phonons (SCOPs) [T. Kampfrath et al., PRL 95, 187403 (2005)] in a semiempirical way . From our simulations we could determine the decay of the SCOPs into other phonon modes, in particular, the out-of-plane lattice vibrations.