Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 28: THz Physics

HL 28.1: Talk

Monday, March 14, 2011, 17:30–17:45, POT 51

Density Dependence of the Excitonic 1s-2p Transition Energy in THz Spectroscopy — •Benjamin Breddermann, Mackillo Kira, and Stephan W. Koch — Department of Physics and Material Sciences Center, Philipps-University Marburg, Renthof 5, D-35032 Marburg

Spectroscopy with optical and terahertz (THz) frequencies provides a versatile tool to probe and control semiconductors on a microscopic level. The excitonic resonances depend very strongly on the carrier density n_eh excited to the semiconductor yielding several many-body phenomena. In other words, one finds excitation-induced dephasing (EID) that bleaches the excitonic resonances from both optical and THz spectra if n_eh is increased enough. All these phenomena are treated fully microscopically with the goal to investigate the influence of these many-body effects in the optical and THz spectra. We report results on the density dependent broadening and red-shift of the 1s-2p transition in the THz spectra and present comparisons with recent experiments.