Regensburg 2010 – wissenschaftliches Programm
HL 60.5: Poster
Donnerstag, 25. März 2010, 18:00–20:00, Poster D1
Coupling plasmons and excitons — •Markus Pfeiffer1,2, Klas Lindfors1,2, Markus Lippitz1,2, Harald Gießen2, Paola Atkinson3, Armando Rastelli3, and Oliver G. Schmidt3 — 1Max Planck Institut für Festkörperforschung, Stuttgart — 24. Physikalisches Institut, Universität Stuttgart — 3IFW Dresden
The spontaneous emission of a single quantum system may be significantly modified by changing the local density of states at the position of the emitter. This allows controlling the light emission properties, e.g., emission rate and direction, using a suitable nanostructure. Plasmon resonant metal structures are a particularly interesting choice since the electromagnetic field is significantly enhanced at the plasmon resonance wavelength. This offers exciting possibilities in both fundamental light-matter studies as well as in applications.
We experimentally investigate the influence of plasmon resonant gold nanostructures on the photoluminescence properties of individual semiconductor quantum dots (QDs). The quantum dots are epitaxially grown AlGaAs/GaAs QDs which are buried a few nanometers beneath the semiconductor surface and photoluminesce at approximately 760 nm wavelength. The advantage of this system is that the optical properties of the QDs are very stable and the transition dipole moments have a fixed orientation. The thin barrier layer allows efficient coupling between the exciton in the quantum dot and a plasmon resonant gold nanostructure on the semiconductor surface. We observe modifications in both the photon emission rate and excited state lifetime when the quantum dot is close to a gold nanostructure.