Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 31: Poster II
HL 31.8: Poster
Dienstag, 26. Februar 2008, 16:30–19:00, Poster D
Spin-orbit coupling in InGaSb/InAlSb and InGaAs/InP 2DEGs — •Vitaliy A. Guzenko1, Masashi Akabori2, Thomas Schäpers1, Sergio Estévez1, Hilde Hardtdegen1, Taku Sato2, Toshi-kazu Suzuki2, and Syoji Yamada2 — 1Institute of Bio- and Nanosystems (IBN 1), Research Centre Jülich, 52425 Jülich, Germany — 2Center for Nano-Materials and Technology (CNMT), Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
Spin-orbit interaction in high-mobility two-dimensional electron gases (2DEGs) formed in high indium content InGaAs-based and InGaSb-based quantum wells was studied. Magnetotransort measurements were performed at low temperatures in a wide range of magnetic field. Characteristic beating pattern in the Shubnikov–de Haas oscillations as well as the enhancement of magnetoconductance at B=0 T due to weak antilocalization (WAL) effect were observed. A comparison of the values of the Rashba spin-orbit coupling parameters estimated from analysis of the beatings with the ones obtained from the fit of the WAL curves showed a good agreement. A control over the strength of the Rashba coupling parameter in the InGaAs 2DEG was achieved by applying a gate voltage. We found that in particular range of the negative gate voltages no beatings can be observed anymore, whereas the weak antilocalization becomes more pronounced. Under such conditions analysis of the WAL is a reliable method to determine the strength of the spin-orbit interaction in 2DEGs.