Regensburg 2010 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 64: Quantum Dots and Wires: Optical Properties VI
HL 64.4: Talk
Friday, March 26, 2010, 11:00–11:15, H14
Effect of biaxial stress on single particle states and binding energies of charged excitons and biexciton in In(Ga)As/GaAs(001) self-assembled quantum dots — •Ranber Singh1, Fei Ding2, Johannes Plumhof2, Tim Zander2, Gabriel Bester1, Armando Rastelli2, and Oliver Schmidt2 — 1Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany — 2Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr 20, D-01069 Dresden, Germany
We study the effect of an external biaxial stress on single particle states and binding energies of charged excitons and biexciton relative to that of neutral exciton in In(Ga)As/GaAs(001) quantum dots. We performed million-atom empirical pseudopotential calculations on realistic In(Ga)As/GaAs(001) quantum dots. We find that compressive biaxial stress increases the electron localization and hole delocalization. The binding energies of the positive trion and biexciton increase under compressive stress. Depending upon the value of binding energy of biexciton and available biaxial stress, the binding energy of biexciton can be tuned to zero which allows for the generation of entagnled photon pairs across generations in biexciton cascade process in In(Ga)As/GaAs(001) self-assembled quantum dots.