SKM 2021 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 13: Poster Session III

HL 13.11: Poster

Tuesday, September 28, 2021, 13:30–16:30, P

Spectral manipulation of coherent acoustic phonons in a graphite nanofilm observed by ultrafast electron diffraction — •Arne Ungeheuer, Ahmed Hassanien, Mashood Mir, Arne Senftleben, and Thomas Baumert — University of Kassel, Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), D-34132 Kassel, Germany

Femtosecond-laser-excited nanomechanical strain-waves in thinfilm-structures allow for a series of quantized resonant modes with amplitudes that depend on the photoinduced spatiotemporal strain-distribution in the material [1]. We investigate the possibilities to amplify specific higher harmonic modes in a graphite nanofilm, employing a NIR femtosecond-laser double pulse excitation-scheme. We present results from ultrafast electron diffraction studies for different relative pulse-delays within the double-pulse sequence, yielding constructive or destructive interference for selected coherent acoustic phonon harmonics.

[1] F. Hudert et al.: Phys. Rev. B 79, 2009.