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HL: Fachverband Halbleiterphysik

HL 55: Quantum Dots and Wires, Optical Properties IV: Spin

HL 55.3: Vortrag

Donnerstag, 25. März 2010, 14:30–14:45, H14

Spin-ensembles in (In,Ga)As/GaAs quantum dots — •Alexander Schwan¹, Stefan Spatzek¹, Steffen Varwig¹, Sophia E. Economou², Alex Greilich¹, Dmitri R. Yakovlev¹, Dirk Reuter³, Andreas D. Wieck³, Thomas L. Reinecke², and Manfred Bayer¹ — ¹Experimentelle Physik II, TU Dortmund, D-44221 Dortmund, Germany — ²Naval Research Laboratory, 20375 Washington DC, USA — ³Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany

Optically controlled electron spins in ensembles of quantum dots (QDs) provide an attractive candidate to implement quantum information technologies in a solid-state environment. Electron spin coherence in an inhomogeneous ensemble of singly charged (In,Ga)As/GaAs QDs was studied by means of time-resolved techniques [1][2].

The inhomogeneity of the QDs allows us to address two different spin-ensembles, separated in energy. For the optical orientation of the spin-ensembles we use two synchronized pulsed Ti:Sapphire lasers, which have a well defined spectral detuning. The temporal evolution of the spin precession of the ensembles is measured by time-resolved Faraday-Rotation. Results are reported for a wide range of excitation parameters.

[1] A. Greilich, D. R. Yakovlev, A. Shabaev, Al. L. Efros, I. A. Yugova, R. Oulton, V. Stavarache, D. Reuter, A. Wieck, and M. Bayer, Science 313, 341 (2006)

[2] A. Greilich, A. Shabaev, D. R. Yakovlev, Al. L. Efros, I. A. Yugova, D. Reuter, A. D. Wieck and M. Bayer, Science 317, 1896 (2007)