Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 52: Quantum dots and wires: Optical properties IV
HL 52.10: Vortrag
Freitag, 31. März 2006, 13:15–13:30, POT 151
Wavelength- and spin-selective addressing of self-organized InAs/GaAs quantum dots by means of spectral hole burning — •Till Warming1, Witlef Wieczorek1, Martin Geller1, Victor Ustinov2, Alexey Zhukov2, and Dieter Bimberg1 — 1Institut für Festkörperphysik, TU Berlin — 2A.F. Ioffe Physico-Technical Institute RAS, St. Petersburg, Russia
Semiconductor quantum dots (QDs) with their possibility to confine one single carrier only, representing one quantum bit of information, are potential candidates for future memory devices. Here, spectral hole burning is used for wavelength-selective addressing of a subensemble of QDs from the large inhomogeneously broadened QD ensemble. Resonant laser excitation and controlled tunneling leads to QDs charged with single carriers. Such charging manifest itself in photocurrent spectra as increased absorption due to the formation of negatively charged trions. Spin-selective addressing by polarized excitation is demonstrated at low temperatures and sufficiently high magnetic fields when pure spin states prevail. The formation of trion depends on the polarization of the primary and secondary pump wi9th respect to each other, in order to take account of Pauli blocking. Spin-selective readout of the carriers is realized. Parts of this work are funded by the European SANDiE NoE, contr. no. NMP4-CT-2004-500101 and SFB296 of DFG.