Dresden 2017 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 63: Poster: Quantum Dots and Optics

HL 63.50: Poster

Mittwoch, 22. März 2017, 15:00–19:00, P1A

Two-color two-photon biexciton generation in single quantum dots — •Björn Jonas, Amlan Mukherjee, Alexander Leier, Alex Widhalm, Nand Lal Sharma, Dirk Reuter, and Artur Zrenner — Center for Optoelectronics and Photonics Paderborn (CeOPP), Universität Paderborn, Paderborn, Germany

Quantum dots are among the best controlled solid state emitters at the single photon level. One particular area of interest is the generation of single photons at emission wavelength different from the excitation wavelength using nonlinear two-photon transitions between the biexciton state and the ground state of quantum dots. A promising approach to gain even more control over the emission wavelength and polarization is to generate single photons by a stimulated downconversion process from the biexciton state. [1] As preliminary work, we performed degenerate (one-color) and nondegenerate (two-color) resonant two-photon biexciton generation in InGaAs-quantum dots embedded in a n-i-Schottky-photodiode. This allows for the detection of the resulting excitations in the photocurrent with good accuracy. We demonstrate two-color two-photon excitation of the biexciton state and compare it to the degenerate process. Furthermore, we measure the biexciton peak amplitude as function of the energy separation between the two excitation lasers.

[1] D. Heinze et al., Nature Communications 6, 8473 (2015).