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HL: Fachverband Halbleiterphysik

HL 120: Ultra-fast phenomena II

HL 120.5: Vortrag

Freitag, 4. April 2014, 12:30–12:45, POT 006

Fractional diffusion in laser-excited silicon — •Tobias Zier, Eeuwe S. Zijlstra, and Martin E. Garcia — Theoretical Physics, University of Kassel, Germany

With an intense ultrashort-laser pulse excitation of crystalline Si one creates a highly nonthermal state, which is characterized by electrons with a temperature of several 10 000 K and ions close to room temperature. Due to this the interatomic bonds can soften or even break for sufficiently high excitations. In the latter case the crystalline structure disorders within several hundreds of femtoseconds. Therefore, this process is called ultrafast melting. The results of our performed ab initio MD-Simulations with supercells containing up to 800 atoms show for the first time that the atoms exhibit fractional diffusion during the ultrafast melting process, a behavior that was up to now only known for big molecules in solutions [1].

[1] E. S. Zijlstra, et al., Adv. Mater. 25, 5605 (2013)