corner
corner

Phys. Rev. B 72, 235306 (2005) [12 pages]

Magneto-optics of two-dimensional electron gases modified by strong Coulomb interactions in ZnSe quantum wells

Download: PDF (1,828 kB) Buy this article Export: BibTeX or EndNote (RIS)

D. Keller1, D. R. Yakovlev2,3, G. V. Astakhov1,3, W. Ossau1, S. A. Crooker4, T. Slobodskyy1, A. Waag5, G. Schmidt1, and L. W. Molenkamp1
1Physikalisches Institut der Universität Würzburg, 97074 Würzburg, Germany
2Experimentelle Physik 2, Universität Dortmund, 44221 Dortmund, Germany
3A. F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
4National High Magnetic Field Laboratory, Los Alamos, New Mexico 87545, USA
5Institute of Semiconductor Technology, Braunschweig Technical University, 38106 Braunschweig, Germany

Received 20 September 2005; revised 11 October 2005; published 5 December 2005

The optical properties of two-dimensional electron gases in ZnSe∕(Zn,Be)Se and ZnSe∕(Zn,Be,Mg)Se modulation-doped quantum wells with electron densities up to 1.4×1012 cm−2 were studied by photoluminescence, photoluminescence excitation, and reflectivity in a temperature range between 1.6 and 70 K and in external magnetic fields up to 48 T. In these structures, the Fermi energy of the two-dimensional electron gas falls in the range between the trion binding energy and the exciton binding energy. Optical spectra in this regime are shown to be strongly influenced by the Coulomb interaction between electrons and photoexcited holes. In high magnetic fields, when the filling factor of the two-dimensional electron gas becomes smaller than 2, a change from Landau-level-like spectra to exciton-like spectra occurs. We attempt to provide a phenomenological description of the evolution of optical spectra for quantum wells with strong Coulomb interactions.

© 2005 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevB.72.235306
DOI:
10.1103/PhysRevB.72.235306
PACS:
78.66.Hf, 71.10.Ca, 71.35.−y, 78.67.De