Dresden 2003 – scientific programme

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SYQI: Quantum information processing in condensed media

SYQI 1: Quantum information processing in condensed media I

SYQI 1.2: Talk

Monday, March 24, 2003, 14:00–14:15, HSZ/01

Optical Rabi Oscillations in an InGaAs Quantum Dot Ensemble — •W. Langbein¹, P. Borri¹, S. Schneider¹, U. Woggon¹, R. L. Sellin², D. Ouyang², and D. Bimberg² — ¹Exp. Physik IIb, Universität Dortmund, Otto-Hahn-Str. 4, 44221 Dortmund — ²Institut für Festkörperphysik TU, Hardenbergstrasse 36, D-10623 Berlin, Germany

We present measurements and calculations of optical Rabi oscillations in the excitonic ground-state transition of an InGaAs quantum dot ensemble at low temperature [1]. We observe Rabi oscillations which are damped versus pulse area and change period when changing pulse duration. Comparisons with calculations show that the observed damping is not intrinsic to a single dot. Dephasing processes and the biexciton resonance change the amplitude and the period of the oscillations, respectively, while the damping versus pulse area is attributed to a distribution of transition dipole moments in the ensemble. Measurements performed at different pulse durations corroborate this interpretation. They also reveal the presence of non-resonant two-photon absorption in the barrier region, covering the Rabi oscillations for short pulse durations.

[1] P. Borri et al., Phys. Rev. B 66, 081306(R) (2002)