Excitonic Polaritons in Transverse Magnetic Fields
D. Loginov
V.A. Fock Institute of Physics, St. Petersburg State University, 198904 St. Petersburg, Russia
V.P. Kochereshko, A. Litvinov
A.F. Ioffe Physico-Technical Institute RAS, 194021 St. Petersburg, Russia
L. Besombes, H. Mariette
Laboratoire de Spectrométrie Physique, Université Joseph Fourier de Grenoble, France
J.J. Davies, L.C. Smith and D. Wolverson
Department of Physics, University of Bath, BA2 7AY Bath, UK
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Received: 9 06 2007;
Reflectivity spectra taken from wide quantum wells based on CdTe/CdZnTe and GaAs/AlGaAs (in which the well width is much larger than the exciton Bohr radius) were studied in magnetic fields in the plane of the well (the Voigt geometry). The energy splitting between bright and dark excitons and the redistribution of the oscillator strength from bright to dark was observed and this allowed us to determine the exciton exchange constant Δ. We found that exciton translational mass depends on the value of magnetic field. Additionally, we found that diamagnetic shift also depends on exciton wave vector. Changes in the spectra in the range of the overlap of heavy and light hole exciton resonances were observed when the magnetic field was inverted. Theoretical modeling of the spectra allowed us to explain all the observed features in the reflectivity spectra and to determine some material parameters.
DOI: 10.12693/APhysPolA.112.381
PACS numbers: 71.35.-y, 71.35.Ji, 78.20.Ls, 78.67.De