Effiziente Quellen polarisationsverschränkter Photonenpaare auf Basis von deterministischen Quantenpunkt-Mikrolinsen

• Antragsteller: Professor Dr. Stephan Reitzenstein
• Fachliche Zuordnung: Experimentelle Physik der kondensierten Materie
• Förderung: Förderung von 2016 bis 2021
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 295465455

In this project, we will develop deterministic and ultra-bright sources of polarization-entangled photon pairs by combining the advantages of In(Ga)As quantum dots (QDs) grown on (111) oriented GaAs substrates, in-situ cathodoluminescence lithography (CLL) of monolithically integrated microlenses, and resonant excitation schemes. These quantum light sources are key elements of advanced quantum communication schemes, such as the quantum repeater, which are based on entanglement distribution. In our concept, single (111) QDs in the active region of the sources will enable the generation of polarization-entangled photon-pairs via the biexciton (XX) - exciton (X) radiative cascade due to the unique electronic structure of these QDs with diminishing fine-structure splitting. Using CLL, such QDs will be deterministically integrated into microlenses which, in combination with lower mirror sections, ensure broadband enhancement of XX and X emission with predicted extraction efficiencies beyond 80 %. The full potential of these quantum light sources will be explored by resonant excitation schemes aiming at the on-demand emission of polarization-entangled photon pairs with record brightness and indistinguishability. To this end, the high potential of our concept in the field of quantum communication will be demonstrated by performing two-photon interference experiments of emission from separated sources under resonant two-photon pi-pulse excitation.

• DFG-Verfahren: Sachbeihilfen
• Internationaler Bezug: Russische Föderation
• Partnerorganisation: Russian Foundation for Basic Research
• Kooperationspartner: Professor Dr. Vladimir Haisler