Dresden 2017 – wissenschaftliches Programm
HL 58.6: Vortrag
Mittwoch, 22. März 2017, 16:45–17:00, POT 151
Inversion of permanent exciton dipole moment in self-assembled In(Ga)As quantum dots by nonlinear piezoelectricity — Johannes Aberl1, •Petr Klenovsky2,3, Johannes S. Wildmann1, Javier Martin-Sanchez1, Thomas Fromherz1, Eugenio Zallo4,5, Josef Humlicek2,3, Armando Rastelli1, and Rinaldo Trotta1 — 1Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstraße 69, A-4040 Linz, Austria — 2Department of Condensed Matter Physics, Masaryk University, Kotlářská, CZ-61137 Brno, Czech Republic — 3Central European Institute of Technology, Masaryk University, Kamenice 753/5, CZ-62500 Brno, Czech Republic — 4Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstraße 20, D-01069 Dresden, Germany — 5Paul-Drude-Institut für Festkörperelektronik, Hausvogteilplatz 5-7, 10117 Berlin, Germany
We show tuning of the electric dipole moment of excitons confined in self-assembled In(Ga)As quantum dots by anisotropic biaxial stress up to complete erasure of its magnitude and inversion of its sign. We attribute this effect to the piezoelectricity due to applied stress, the magnitude of which we estimate using a simple model based on the piezotronic effect. Self-consistent k→.p→ calculations reveal that the strain-induced changes of the dipole moment in our QDs that we observe can be only accounted for by the nonlinear piezoelectric effect, the importance of which in QD-physics has been theoretically recognized but it proved to be difficult to single out experimentally.