Enhanced sequential carrier capture into individual quantum dots and quantum posts controlled by surface acoustic waves

Abstract

Individual self-assembled Quantum Dots and Quantum Posts are studied under the influence of a surface acoustic wave. In optical experiments we observe an acoustically induced switching of the occupancy of the nanostructures along with an overall increase of the emission intensity. For Quantum Posts, switching occurs continuously from predominantely charged excitons (dissimilar number of electrons and holes) to neutral excitons (same number of electrons and holes) and is independent on whether the surface acoustic wave amplitude is increased or decreased. For quantum dots, switching is non-monotonic and shows a pronounced hysteresis on the amplitude sweep direction. Moreover, emission of positively charged and neutral excitons is observed at high surface acoustic wave amplitudes. These findings are explained by carrier trapping and localization in the thin and disordered two-dimensional wetting layer on top of which Quantum Dots nucleate. This limitation can be overcome for Quantum Posts where acoustically induced charge transport is highly efficient in a wide lateral Matrix-Quantum Well.

11 pages, 5 figures

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• Direct Observation of Controlled Coupling in an Individual Quantum Dot Molecule
• Recent advances in exciton based quantum information processing in quantum dot nanostructures
• Photoluminescence Spectroscopy of the Molecular Biexciton in Vertically Stacked Quantum Dot Pairs
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Cited by in corpus (9)

• Dynamic modulation of photonic crystal nanocavities using gigahertz acoustic phonons
• Dynamic Acoustic Control of Individual Optically Active Quantum Dot-like Emission Centers in Heterostructure Nanowires
• Directional and dynamic modulation of the optical emission of an individual GaAs nanowire using surface acoustic waves
• Independent dynamic acousto-mechanical and electrostatic control of individual quantum dots in a LiNbO${}_3$-GaAs hybrid
• Direct observation of dynamic surface acoustic wave controlled carrier injection into single quantum posts using phase-resolved optical spectroscopy
• Radio frequency occupancy state control of a single nanowire quantum dot
• Surface acoustic wave controlled charge dynamics in a thin InGaAs quantum well
• Surface acoustic wave mediated carrier injection into individual quantum post nano emitters
• Inter-dot coupling and excitation transfer mechanisms of telecommunication band InAs quantum dots at elevated temperatures