Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 95: Quantum Dots and Wires: Optical Properties III (mainly Cavities and Ultrafast Response)
HL 95.7: Vortrag
Freitag, 30. März 2012, 11:00–11:15, EW 201
On the treatment of carrier scattering in quantum dots beyond the Boltzmann equation — •Alexander Steinhoff1, Matthias Florian1, Paul Gartner1,2, and Frank Jahnke1 — 1Institute for Theoretical Physics, University of Bremen, Germany — 2National Institute of Materials Physics, Bucharest-Magurele, Romania
As quantum dots (QD) can confine a small number of carriers in localized states with discrete energies, it is clearly questionable to neglect correlations between the carriers when describing their dynamics. We discuss the effects of carrier correlations in a single QD in contact with a wetting layer (WL) by comparing the carrier dynamics without correlations between the QD-carriers, as given by a Boltzmann equation, with the correlated dynamics governed by a Liouville-von Neumann equation. In a first step, we take into account correlations generated by the exact treatment of Pauli blocking. Subsequently, we include correlations generated by energy renormalizations due to Coulomb interaction between the QD-carriers. It is shown that at low WL-carrier densities, neither Pauli correlations nor Coulomb correlations can be safely neglected, if the dynamics of single-particle states in the QD are to be predicted qualitatively and quantitatively. In the high-density regime, both types of correlations play a lesser role and thus an uncorrelated description of carrier dynamics by a Boltzmann equation becomes reliable. Furthermore, the efficiency of WL-assisted scattering processes as well as scattering-induced dephasing rates depending on the WL-carrier density are discussed.