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HL: Fachverband Halbleiterphysik

HL 77: Quantum Dots and Wires: Optical Properties II (mainly Luminescence and Electronic Structure)

HL 77.3: Talk

Thursday, March 29, 2012, 10:00–10:15, EW 203

Vertical electric field tuning of exciton fine structure splitting in strain-free GaAs/AlGaAs(001) quantum dots — ranber singh and •gabriel bester — Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany

We investigate the vertical electric field tuning of exciton fine structure splitting (FSS) in strain-free GaAs/AlGaAs(001) quantum dots. We find that the bright exciton lines anticross. However, the anticrossing is very small so that the FSS in strain-free GaAs/AlGaAs quantum dots can be easily tuned to below the radiative linewidth (≈1µeV) by applying vertical electric field along the growth direction. The vertical electric field tuning of FSS is also advantageous because it does not reduce the oscillator strength of exciton transitions in contrast to the significant reduction in case of lateral electric field.