Berlin 2014 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 30: Poster: Photonics, laser development and applications, ultrashort laser pulses, quantum effects

Q 30.60: Poster

Dienstag, 18. März 2014, 16:30–18:30, Spree-Palais

Influence of band structures in strong-field phenomena in solids — •Takuya Higuchi and Peter Hommelhoff — Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen

Advances in phase-stabilized pulsed lasers have opened an avenue to field-induced nonlinear optical phenomena, such as field ionisation and higher-harmonic generation. The scope of these strong-field phenomena has been mainly focused on gaseous media, and is extended to solids more recently. A notable difference of crystalline solids from individual gas atoms or molecules is the existence of periodicity due to the lattices, where electrons form band structures in the reciprocal space. The role of this periodicity in perturbative light-matter interactions has been well explored, however, can differ quite much in such strong field phenomena and waits for deeper understanding. For example, Bragg reflection at the Brillouin zone boundaries and formation of Wannier-Stark localized states are known to play important roles, where the wave-number dependence of the energies of the electron bands are essential. However, the energies of the bands are not the only parameters that depend on the wave number. In this contribution, we highlight the influence of the wave-number dependence in dipole matrix elements between electron bands on the strong-field phenomena, mainly comparing models for direct- and indirect-band-gap materials. The relationships among Wannier-Stark localization, Zener tunneling, and higher harmonic generations are discussed.