Berlin 2015 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 95: Poster IV B (Quantum dots and wires: Prepration, characterization, optical properties, and transport)
HL 95.22: Poster
Donnerstag, 19. März 2015, 14:00–20:00, Poster B
Numerical Investigation of the Nonlinear Optical Properties of Quantum Dot Molecules (QDM) — •Peter Kölling and Jens Förstner — Universität Paderborn, Germany
We theoretically study the optical properties of epitaxially grown InAs quantum dot molecules which are integrated in Schottky diode structures. From optical experiments one knows that the electronic states inside the single quantum dots are coupled [1]. Applying gate voltages at these diode structures allows manipulation of the relative energies inside the single quantum dots as well as manipulation of carrier tunneling between the dots [2,3]. This in turn can be used to achieve switching between electronic states at nano- or picosecond time scales. Nonlinearities arise due to the excitation of exciton complexes with variable numbers of electrons and holes.
To fully understand and control these processes one has to understand the electronic structure of the coupled systems as well as the excitation dynamics within these systems. We investigate single particle eigenenergies and eigenstates by means of k·p-theory with the nextnano3 software package [4]. Results from these calculations are then used as input paramters for Heisenberg equations of motion for a reduced density operator.
[1] G. Ordner et al., Phys. Rev. Lett. 94, 157401 (2006)
[2] E. A. Stinaff et al., Science 311, 636-639 (2006)
[3] M. Schreibner et al., Solid State Comm. 149, 1427-1435 (2009)
[4] http://www.nextnano.de/nextnano3/