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arXiv · 1611.06117

Density dependent exciton dynamics and L valley anisotropy in germanium

Markus Stein·Christian Lammers·Phillip Springer·Philipp-Henrik Richter·Stephan W. Koch·Mackillo Kira·Martin Koch
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Abstract

Optical pump-THz probe spectroscopy is used to investigate the exciton formation dynamics and its intensity dependence in bulk Ge. Associated with the intra-excitonic 1s-2p transition, the gradual build-up of an absorption peak around 3.1 meV (0.75 THz) signifies the delayed exciton formation after optical pump which is accelerated for higher excitation densities. Analyzing the spectral shape of this THz absorption resonance, two distinct resonances are found which are attributed to the mass-anisotropy of L valley electrons via a microscopic theory.

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Markus Stein, Christian Lammers, Phillip Springer, Philipp-Henrik Richter, Stephan W. Koch, Mackillo Kira, Martin Koch. 2016-11-18. Density dependent exciton dynamics and L valley anisotropy in germanium. https://doi.org/10.1103/physrevb.95.155207

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