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Title: High magnetic field studies of charged exciton localization in GaAs/Al{sub x}Ga{sub 1−x}As quantum wells

We report on low temperature, polarization resolved, high magnetic field (up to 23 T) photoluminescence experiments on high mobility asymmetric GaAs quantum wells. At high magnetic fields, we detect two strong emission lines of the neutral and positively charged excitons (X and X{sup +}) and a series of weaker lines of the excitons bound to ionized acceptors (AX{sup −}). From polarization energy splittings of these lines, we determine the hole Landé factors (g{sub h}) of different complexes. For X and X{sup +}, g{sub h} initially grows with magnetic field and then saturates at g{sub h} = 0.88 and 1.55, respectively; for AX{sup −}'s, g{sub h} begins from a high value (from 6 to 11 at zero field) and decreases with the field growth. This contrasting behavior is traced to the structure of valence band Landau levels, calculated numerically in the Luttinger model, beyond axial approximation. This points to the coexistence (in the same well) of mobile X and X{sup +} with localized and interface-pressed AX{sup −} states.
Authors:
; ; ; ;  [1] ;  [2] ;  [3] ; ;  [3] ;  [4] ; ; ;  [5]
  1. Institute of Physics, Wrocław University of Technology, 50-370 Wroclaw (Poland)
  2. Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, Grenoble (France)
  3. Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund (Germany)
  4. (Russian Federation)
  5. Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 OHE (United Kingdom)
Publication Date:
OSTI Identifier:
22303512
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTROSCOPY; ALUMINIUM COMPOUNDS; APPROXIMATIONS; ASYMMETRY; CARRIER MOBILITY; COMPUTERIZED SIMULATION; CRYSTAL GROWTH; EXCITONS; GALLIUM ARSENIDES; HOLES; INTERFACES; MAGNETIC FIELDS; PHOTOLUMINESCENCE; POLARIZATION; QUANTUM WELLS; X-RAY SPECTROSCOPY