Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 50: Ultra fast phenomena

HL 50.4: Vortrag

Freitag, 27. März 2009, 11:00–11:15, BEY 118

Quantum dynamical study of the amplitude collapse and revival of coherent A1g phonons in bismuth: A classical phenomenon? — •Momar S. Diakhate, Eeuwe S. Zijlstra, and Martin E. Garcia — Theoretische Physik, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany.

We parametrize the potential energy surface of bismuth after intense laser excitation using accurate full-potential linearized augmented plane wave calculations.Anharmonic contributions up to the fifth power in the A1g phonon coordinate are given as a function of the absorbed laser energy. Using a previously described model including effects of electron-phonon coupling and carrier diffusion [S. L. Johnson et al.: Phys.Rev. Lett. 100, 155501 (2008)] we obtain the time-dependent potential energy surface for any given laser pulse shape and duration. On the basis of this parametrization we perform quantum dynamical simulations to study the experimentally observed amplitude collapse and revival of coherent A1g phonons in bismuth [O. V. Misochko et al.: Phys.Rev. Lett. 92, 197401 (2004)]. Our results strongly indicate that the observed beatings are not related to quantum effects and are most probably of classical origin.