Level degeneracy and temperature-dependent carrier distributions in self-organized quantum dots

Abstract

Using femtosecond three-pulse pump–probe spectroscopy, we investigated the transparency condition for the ground and first excited states in self-organized In0.4Ga0.6AsIn0.4Ga0.6As quantum dots at different temperatures and wavelengths. The temperature-dependent behavior of the transparency condition is consistent with calculations using a multilevel model with a large density of states in the quantum-well reservoir. The twofold spatial degeneracy of the first excited state and the temperature dependence of the thermal equilibrium processes were experimentally observed. © 2003 American Institute of Physics.