We investigate the dynamics of electrons injected into InAs/GaAs quantum dots by initializing and further observing the spin state of the electrons. For this purpose, we use spin polarized light-emitting diodes where the electron spin is set in a semimagnetic ZnMnSe layer. We find that the degree of optical polarization depends strongly on the ground state energy of the quantum dot. A dependence of polarization on dopant concentration in the spin aligner suggests an influence of residual electrons in the quantum dots.
W. Löffler, N. Höpcke, C. Mauser, J. Fallert, T. Passow, B. Daniel, S. Li, D. Litvinov, D. Gerthsen, H. Kalt, M. Hetterich
J. Phys. Conf. Ser. 61, 745 (2007)