SKM 2021 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 19: Poster Session IV

HL 19.28: Poster

Donnerstag, 30. September 2021, 13:30–16:30, P

Nonlinear down-conversion in a single quantum dot — •Björn Jonas, Dirk Heinze, Eva Schöll, Patricia Kallert, Timo Langer, Sebastian Krehs, Alex Widhalm, Klaus D. Jöns, Dirk Reuter, Stefan Schumacher, and Artur Zrenner — Paderborn University, Physics Department, Warburger Straße 100, 33098 Paderborn, Germany

In our work we study an all optical approach based on nonlinear principles, to tune the emission of the biexciton state in a single quantum dot[1]. After preparation of the biexciton state via phonon-assisted two-photon excitation, we introduce a control-laser which enables a nonlinear down-conversion via a virtual state. Previous theoretical work suggests that the spectral and polarization properties of this stimulated emission can be fully controled by adjusting the respetive properties of the control-laser[2]. In this work we show the first experimental demonstration of this process. The stimulated down-conversion works best if the virtual state is tuned close to the exciton energy and we can achieve a tuning range of about 0.5 meV around the exciton and biexciton emission. We furthermore make use of the spin conservation in the system to demonstrate control of the polarization of the emitted photon.

[1] http://arxiv.org/abs/2105.12393
[2] D. Heinze et al., Nature Communications 6, 8473 (2015)