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arXiv · 1012.1762

Elementary excitations in charge-tunable InGaAs quantum dots studied by resonant Raman and resonant photoluminescence spectroscopy

Tim Köppen·Dennis Franz·Andreas Schramm·Christian Heyn·Johann Gutjahr·Daniela Pfannkuche·Detlef Heitmann·Tobias Kipp
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Abstract

We report on resonant optical spectroscopy of self-assembled InGaAs quantum dots in which the number of electrons can accurately be tuned to N=0,1,2 by an external gate voltage. Polarization, wave vector and magnetic field dependent measurements enable us to clearly distinguish between resonant Raman and resonant photoluminescence processes. The Raman spectra for N=1 and 2 electrons considerably differ from each other. In particular, for N=2, the quantum-dot He, the spectra exhibit both singlet and triplet transitions reflecting the elementary many-particle interaction. Also the resonant photoluminescence spectra are significantly changing by varying the number of electrons in the QDs. For N=1 we observe strong polaronic effects which are suppressed for N=2.

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Tim Köppen, Dennis Franz, Andreas Schramm, Christian Heyn, Johann Gutjahr, Daniela Pfannkuche, Detlef Heitmann, Tobias Kipp. 2010-12-08. Elementary excitations in charge-tunable InGaAs quantum dots studied by resonant Raman and resonant photoluminescence spectroscopy. https://doi.org/10.1103/physrevb.83.165307

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