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, we focus on three major goals:

(1) Develop novel excitation methods to coherently control the QD excited states [1,2,3], with the goal of:

(2) Generating high-quality single-photon states [4], or time-bin entangled photon states [5,6]. Our ambitious FWF project AEQuDot is a collaboration with Doris Reiter and Armando Rastelli, see [7,8] for the theory details.

(3) Designing and fabricating photonic cavity structures on QDs for high brightness single photons [9] for our multiphoton interference experiments in our FWF project FG5: Multiphoton Experiments with Quantum Dots with Prof. Armando Rastelli, and Prof. Philipp Walther

(4) Engineering collective effects in interacting dipole emitters, in our FWF project DarkEneT, and quantA Cluster of Excellence Project with Helmut Ritsch and Armando Rastelli

We mostly work with InAs/GaAs quantum dots grown and/or provided by our various collaborators: D. Dalacu and P. Poole (NRC Ottawa), A. Rastelli (JKU Linz).

[1] Adv. Quantum Technol. 2024, 2300352 https://doi.org/10.1002/qute.202300352

[2] APL Photonics 8 , 101301 (2023) https://doi.org/10.1063/5.0164222, Mater. Quantum. Technol. 3, 025006 (2023), https://iopscience.iop.org/article/10.1088/2633-4356/acd7c1

[3] Nano Lett. 22 6567 (2022) https://doi.org/10.1021/acs.nanolett.2c01783

[4] npj Quantum Inf. 2024 (accepted) arxiv.org/abs/2305.20017

[5] Phys. Rev. Lett. 121 , 110503 (2018). http://doi.org/10.1103/PhysRevLett.121.110503

[6] AIP Advances 12 , 055115 (2022). https://doi.org/10.1063/5.0081874

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

[8] Phys . Rev. B 104 , 075428 (2021), https://doi.org/10.1103/PhysRevB.104.075428

[9] M. Weinreich, Master's thesis, 2022-23

Links to our Projects:

[P1] https://www.fwf.ac.at/forschungsradar/10.55776/COE1

[P2] https://www.fwf.ac.at/forschungsradar/10.55776/I4380

[P3] https://www.fwf.ac.at/forschungsradar/10.55776/FG5

[P4] https://www.fwf.ac.at/forschungsradar/10.55776/TAI556

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