Charge and spin storage in self-organized quantum dots

We demonstrate optical charging of spectrally selected subensembles of self-organized quantum dots with single charge carriers. In spectral hole burning experiments negative and positive trions are observed, representing quantum dots charged with single electrons and holes. By circularly polarized excitation in an applied magnetic field we are able to address the spin of single electrons. A spin flip of the electron is observed after excitation in the upper Zeeman level. (c) 2006 American Institute of Physics.