Berlin 2008 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

O: Fachverband Oberflächenphysik

O 11: Time-Resolved Spectroscopy I

O 11.4: Talk

Monday, February 25, 2008, 14:15–14:30, MA 043

Potential Energy Surface of Laser-Excited InSb — •Jessica Walkenhorst, Eeuwe S. Zijlstra, and Martin E. Garcia — Theoretische Physik, Fachbereich Naturwissenschaften, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel

A recent experiment [A. M. Lindenberg et al., Science 308, 392 (2005)] performed on InSb suggests that ultrafast laser-induced nonthermal melting occurs due to a flattening of interatomic potentials. This study was based on Debye-Waller theory, applied in the time-domain and for non-equilibrium processes. We analyzed the nonthermal melting of InSb by using (i) first-principles electronic structure calculations for the interatomic potentials (ii) dynamical models to find the structure factors under different nonequilibrium conditions. Our calculations show that no dramatic flattening of the potential energy surface occurs. Instead, the softening of the transverse acoustic phonons at the X point suffices to explain the measured Gaussian x-ray intensity decay.