Matthias Löbl

Low-Noise GaAs Quantum Dots for Quantum Photonics

We have realized electrical tuning of the energy and the charge-state of GaAs quantum dots in AlGaAs. In contrast to previous work on the same system, the quantum dots do not suffer from a fluctuating charge-state. At the same time, we achieve linewidths that are just a few percent broader than the lifetime-limit. Our results

Large-Range Frequency Tuning of a Narrow-Linewidth Quantum Emitter

We have achieved large-range frequency tuning of a single-photon emitter, a GaAs quantum dot in a bulk sample. The total tuning range is three orders of magnitude large than the quantum dot’s linewidth, which remains narrow throughout the entire tuning process. Our results are an important step towards building a hybrid system connecting a single-photon

Radiative Auger process in the single-photon limit

We report a radiative Auger process for a trion in a semiconductor quantum dot. The process allows us to measure the quantum mechanical energy separations and the carrier dynamics in the quantum dot. The results have been published in Nature Nanotechnology.

Excitons in InGaAs quantum dots without electron wetting layer states

We have recently shown that InGaAs quantum dots can be grown without conduction band states of the so-called wetting layer. This work is the result of a collaboration with the Ruhr Universität Bochum and the Forschungszentrum Jülich. In the picture below, you see a transmission electron microscopy image of a quantum dot grown with the