Selective optical charge generation, storage, and readout in a single self-assembled quantum dot

We report the investigation of a single quantum dot charge storage device. The device allows selective optical charging of a single dot with electrons; storage of these charges over timescales much longer than microseconds. Reliable readout of the charge occupancy is realized by the time gated photoluminescence technique. This device enables us to investigate the tunneling escape of electrons at high electric fields up to several microseconds and, therefore, demonstrates that with more elaborate pulse sequences such structures can be used to investigate charge and spin dynamics in single quantum dots.