Regensburg 2004 – scientific programme
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HL: Halbleiterphysik
HL 36: Quantenpunkte und -dr
ähte: Optische Eigenschaften I
HL 36.3: Talk
Thursday, March 11, 2004, 10:45–11:00, H17
Investigation of the coupling-dependence on the dephasing in coupled quantum dots — •Matthias Schwab1, P. Borri1, W. Langbein1, U. Woggon1, M. Bayer1, S. Fafard2, Z. Wasilewski2, and P. Hawrylak2 — 1Experimentelle Physik II, Otto-Hahn Strasse 4, 44221 Dortmund, Germany — 2Institute for Microstructural Science, National Research Concil, Ottawa, K1A 0R6, Canada
Due to their atom-like density of states semiconductor quantum dots (QD) are often referred to as artificial atoms. QDs receive a lot of attention as they are possible candidates in the field of quantum information and cryptography. By shrinking the distance between two QDs, one can bring the single-particle wave function to an overlap creating so called semiconductor quantum dot molecules.
A prerequisite for any application of their quantum mechanical properties is a detailed knowledge of their electronic levels and their coupling to the environment.
In this talk we report on measurements of the dephasing times of the exciton in InAs/GaAs quantum dot molecules having different interdot barrier thicknesses. A heterodyne four-wave-mixing (FWM) technique is used to measure the dephasing times in a temperature range from 5 K to 60 K. The results are compared to a quantum dot single layer. Systematic dependencies of the homogeneous linewidth on barrier thickness and on the temperature are reported.