Berlin 2005 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 4: Quantenpunkte und -dr
ähte: Optische Eigenschaften I
HL 4.5: Vortrag
Freitag, 4. März 2005, 11:45–12:00, TU P-N201
Electron and hole storage in InAs/GaAs quantum dots — •Witlef Wieczorek1, Till Warming1, Martin Geller1, Viktor M. Ustinov2, Alexey Zhukov2, and Dieter Bimberg1 — 1Institut für Festkörperphysik, TU Berlin — 2Ioffe Physico-Technical Institute RAS, St. Petersburg, Russia
Semiconductor quantum dots (QDs) with their possibility to confine single carriers representing one quantum bit of information are possible candidates for future memory devices. The potential of inhomogeneously broadened, self-organized QDs for parallel optical storage is demonstrated by spectral hole burning experiments. We investigate different MBE-grown InAs/GaAs quantum dot structures in order to store either holes or electrons as memory carriers. We demonstrate storage of electrons in QDs: By laser excitation a homogeneously broadened ground state of the QDs is charged leading to a spectrally shifted absorption due to few particle effects in the QDs. This is seen in a photocurrent spectrum as a red shifted, negatively charged Trion relative to the ground state. Storage of electrons opens the opportunity to do spin polarized measurements which are interesting for memory applications and quantum computing. Parts of this work are funded by the European SANDiE NoE, contract no. NMP4-CT-2004-500101 and SFB296 of DFG.