Fabrication of drop-etched quantum dots that glow in the optical C-band.

Symbolic image (University of Paderborn, Besim Mazhiqi) - Researchers from the Department of Physics and the Institute for Photonic Quantum Systems (PhoQS) in Paderborn have successfully produced quantum dots - nanoscopic structures in which the quantum properties of matter come into play - that glow in the optical C-band at a wavelength between 1530 and 1565 nanometers as part of a project funded within the Collaborative Research Center/TRR 142. What is special is that this is the first time that such quantum dots have been successfully fabricated by local droplet etching and subsequent filling of the nano-holes in the indium aluminum arsenide/indium gallium arsenide system in a lattice-matched manner on indium phosphide substrates. In the future, these quantum dots may be used, for example, as a source of entangled photons, which may become relevant for novel encryption systems using quantum technologies. Of particular importance is the luminescence in the optical C-band: at this wavelength, the attenuation in the fiber optic network is minimal, so a possible future use is possible with the current network. The scientists have now published their results in the journal -AIP Advances-. The team of Dennis Deutsch, Christopher Buchholz, Dr. Viktoryia Zolatanosha, Klaus Jöns and Dirk Reuter etched nanoscopic holes in an indium aluminum arsenide surface and filled them with indium gallium arsenide. -A critical point in the fabrication of quantum dots, if they are to be used for the generation of entangled photons, is the lattice matching.