Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 13: Poster 1
HL 13.14: Poster
Montag, 26. März 2007, 15:00–17:30, Poster A
FIR Spectroscopy on Carbon-doped Two-Dimensional Hole Systems — •Kevin Rachor1, Carsten Graf von Westarp1, Detlef Heitmann1, Dirk Reuter2, and Andreas Wieck2 — 1Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg — 2Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum
The recent development of Carbon-doped AlGaAs heterostructures on (100) substrates permits an experimental access to two-dimensional hole systems (2DHS) with high mobilities and no anisotropy [1]. Using a Fourier transform spectrometer we perform broadband far infrared transmission experiments on such samples. Cyclotron resonances measured in perpendicular magnetic fields up to 14 T at 1.6 K are presented here revealing the complicated band structure of hole systems. The dispersion is non-linear yielding an increasing effective mass form m* = 0.40 me to 0.42 me for increasing magnetic fields. For B smaller than 11 T the cyclotron resonances splits into two resonances. Tilting the sample increases this splitting. A possible explication is a coupling between the cyclotron (intraband) and the heavy hole-light hole intersubband resonance. Surprisingly, additional broadenings of the cyclotron resonance for magnetic fields higher than 12 T are observed.
The authors are grateful to the DFG for support through SFB 508.
[1] B. Grbić, C. Ellenberger, T. Ihn, K. Ensslin, D. Reuter, and A. D. Wieck. Magnetotransport in C-doped AlGaAs heterostructures. Appl. Phys. Lett. 85, 2277 (2004).