Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 63: Poster: Quantum Dots and Optics

HL 63.22: Poster

Wednesday, March 22, 2017, 15:00–19:00, P1A

High precision microscopic setup for optical analysis of nanostructures — •Magnus Neumann, Jens Hübner, and Michael Oestreich — Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstrasse 2, D-30167 Hannover

Here, we design and characterize a confocal microscope applicable for transmission Faraday-rotation spectroscopy. By photoluminescence measurements on a quantum dot sample with moderate QD density we determined the spatial resolution and absolute repeatability. The high precision microscopic setup provides will enable us to record high resolution photoluminescence maps of transition metal dichalcogenides (TMDC) monolayers. This material system is a promising building block for establishing valleytronic devices as their valley degree of freedom becomes both optically accessible and tunable for single layer structures [1]. The high binding energies of the resulting excitons make TMDCs favorable for room temperature applications. However, the investigation of micrometer-sized monolayers requires high spatial resolution and mechanical stability of the employed optical set-ups. As a next step, we plan to examine the rich spin physics of TMDC monolayers by all-optical spin-noise-spectroscopy [2], as our setup is both suitable for reflection and transmission measurements. SNS does not rely on the high absorption coefficient of TMD Monolayers, leaving the sample in thermal equilibrium and thus revealing the intrinsic spin dynamics.

[1] G. Wang et al., PRL 117, 187401 (2016).

[2] J. Hübner, F. Berski, R. Dahbashi and M. Oestreich, phys. stat. sol. (b) 251, 1824 (2014).