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Biexcitons

  • Wilfried Schäfer
  • Martin Wegener
Part of the Advanced Texts in Physics book series (ADTP)

Abstract

In close analogy to the hydrogen molecule, formed by the binding of two hydrogen atoms, two excitons of opposite spin can form a bound state, called a biexciton. It is clear that the reduction of the energy of two excitons by the additional biexciton binding energy E bi is yet smaller than the exciton binding energy E R itself. As a rule of thumb, Hayne’s rule [198] tells us that the biexciton binding energy in three dimensions is 10% of the exciton binding energy. In quantum wells, the experimental results indicate a value of 20%. For two excitons of equal spin, on the other hand, the interaction is effectively repulsive. This behaviour is obtained even within the Hartree-Fock approximation, where the effective exciton-exciton exchange interaction arising from the Pauli exclusion principle leads to a blueshift of the exciton as discussed in Sect. 6.3. The effective force remains repulsive if correlation effects are included.

Keywords

Circular Polarization Pump Pulse Nonlinear Absorption Interaction Contribution Exciton Density 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • Wilfried Schäfer
    • 1
  • Martin Wegener
    • 2
  1. 1.Forschungszentrum Jülich GmbHJohn von Neumann - Institut für ComputingJülichGermany
  2. 2.Institut für Angewandte PhysikUniversität Karlsruhe (TH)KarlsruheGermany

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