Hamburg 2001 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 7: Poster I

HL 7.33: Poster

Montag, 26. März 2001, 10:30–19:00, Rang S\ 3

DEPOLARIZED RAMAN SCATTERING OF SHORT PERIOD SUPERLATTICES — •de Carvalho dos Anjos Virgilio¹, Nunes L. A. O.², and Bell M. J. V.³ — ¹I. Institut fuer Theoretische Physik, Jungiusstrasse 9, Universitaet Hamburg, D-20355 Hamburg — ²Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, SP, Brazil — ³Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil

The spectra of intersuband excitations of spin-density in electron gases of short period delta-doping superlattices is experimentally and theoretically investigated. The experiments on multilayer GaAs with Si-delta doping profiles with various carrier densities and periods are conducted in extreme resonance regime with the spin-split edge of GaAs. We show that as the periods decreases it is necessary to include the dynamic effect of the creation of holes in the valence band. Such effect renormalize mainly the outermost eletronic subbands energies in the conduction band which have a spatially direct superposition with the holes wave functions. As a result the low energy structures of the depolarized Raman spectra which represent excitations between the quasi-free electrons subbands are red-shifted. Additionally, we demonstrate definitively that depending on the values of the incident laser energy, the spectra may vary from one of pure Raman character to one basically composed by hot luminescence, ending a discussion that has been posed for a long time of which was the character of the spectral lines that appear in the high energy side.