Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 9: Poster I
HL 9.9: Poster
Montag, 27. März 2006, 15:15–17:45, P3
Temperature Dependence of the Electron g Factor in GaAs — •Stefanie Döhrmann1, Roland Winkler1,2, Daniel Hägele1, and Michael Oestreich1 — 1Universität Hannover, Institut für Festkörperphysik, Abteilung Nanostrukturen, Appelstr. 2, 30167 Hannover — 2Northern Illinois University, Department of Physics, De Kalb, IL 60115, USA
We present detailed high precision measurements of the electron Landé factor g* in weakly n-doped GaAs. Using time- and polarization resolved spin quantum beat spectroscopy in an external magnetic field, we determine g* in a temperature range from 2 K to 300 K. At low temperatures, we find a strong interaction between the electron and nuclear spin system. The resulting dynamic nuclear polarization (DNP) acts as an additional magnetic field which drastically affects the measured g*. The value of the bare g* can be determined accurately by monitoring the time dependent DNP. We systematically investigate the dependence of g* on excitation polarization, excitation energy, excitation density, external magnetic field and temperature. The measured temperature dependence of g* shows the opposite trend compared to k·p calculations.