Regensburg 2007 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 31: Quantum dots and wires: Optical properties III
HL 31.9: Talk
Wednesday, March 28, 2007, 17:00–17:15, H17
Influence of a lateral electric field on a semiconductor quantum dot — •Sandra Ritter1, Norman Baer1, Paul Gartner1,2, and Frank Jahnke1 — 1Institute for Theoretical Physics, University of Bremen, Germany — 2National Institute for Material Physics, Bucharest-Magurele, Romania
We study semiconductor quantum dots in a homogeneous electric field which is oriented perpendicular to the growth direction. Assuming a harmonic confinement potential, three different methods for determining the single excitonic ground state are compared.
The first one determines the transition energies of the interacting system where Coulomb matrix elements are calculated from single-particle wave functions in the electric field. It can be solved analytically and gives insight into different physical mechanisms.
The second one minimizes the whole system energetically by using a variational procedure. This method is more accurate since it gives a smaller 1X ground state energy. However, its accuracy relies on a suitable choice of the test function.
For the third method it is assumed that the electron and hole single particle energies are identical. Then the Hamiltonian can be separated into a field independent center-of-mass contribution and a relative motion part that is subject to the electric field. The resulting shifts of the transition energies due to the electric field are determined.