Quantum Dots

Side excitation The future of photonic quantum technologies relies on bright, photostable, and on-demand sources of single and indistinguishable photons. In the search for such perfect quantum light sources, semiconductor quantum dots (QD) have recently emerged as promising platforms with excellent performance characteristics. QDs benefit from their excellent photostability, nearly Fourier-limited emission linewidth, and growth technologies that allow easy integration into nanoscale devices.

In our research subgroup on Quantum Dots, recently we are focussed towards three major goals:

(1) Develop novel excitation protocols to generate and coherently control the QD excited state, see our recent paper

(2) Generate time-bin entangled photon states from QDs [1-3]. To improve this and to get towards deterministic generation of such states, we have recently started investigating the preparation of the biexciton state via dark exciton state in our ambitious FWF project AEQuDot, with Prof. Doris Reiter and Prof. Armando Rastelli, see [4] for the theoretical protocol.

(3) Designing and fabricating photonic cavity structures on QDs for high brightness single photons for our multiphoton interference experiments in our FWF project FG5: Multiphoton Experiments with Quantum Dots with Prof. Armando Rastelli, Prof. Philipp Walther, and Prof. Barbara Kraus

(4) Designing quantum dot nanopillar structures to engineer collective effects like subradiance, towards understanding the energy trapping mechanisms in natural light-harvesting complexes in our latest FWF TAI project DarkEneT: Engineering Dark modes for Energy Trapping

We mostly work with InAs/GaAs quantum dots grown and/or provided by our various collaborators: P. Michler (U. Stuttgart), E. Pelucchi (Tyndall National Institute), P. Poole (NRC Ottawa), A. Rastelli (U. Linz), G. Solomon (NIST Gaithersburg).

[1] Jayakumar et al. https://doi.org/10.1038/ncomms5251

[2] Aumann et al. https://arxiv.org/abs/2102.00283

[3] Prilmueller et al. https://doi.org/10.1103/PhysRevLett.121.110503

[4] Lueker et al. https://doi.org/10.1103/PhysRevB.92.201305

Our past works were supported by the ERC Starting Grant "EnSeNa - Entanglement from Semiconductor Nanostructures" (No. 257531)