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HL: Fachverband Halbleiterphysik
HL 25: Poster 1
HL 25.82: Poster
Wednesday, September 7, 2022, 18:00–20:00, P2
Quantum efficiency boost by photoneutralization of charges in GaAs quantum dots based entangled photon emitters — Jingzhong Yang1, •Tom Fandrich1, Frederik Benthin1, Robert Keil2, Nand Lal Sharma2, Weijie Nie2, Caspar Hopfmann2, Oliver G. Schmidt2,3,4, Michael Zopf1, and Fei Ding1,5 — 1Institut für Festkörperphysik, Leibniz Universität Hannover — 2Institute for Integrative Nanosciences, Leibniz IFW Dresden — 3Material Systems for Nanoelectronics, Technische Universität Chemnitz — 4Nanophysics, Faculty of Physics and Würzburg-Dresden Cluster of Excellence ct.qmat, TU Dresden — 5Laboratorium für Nano- und Quantenengineering, Leibniz Universität Hannover
Single- and entangled-photon sources are a key component of photonic applications in i.e. quantum communication. GaAs quantum dots are very promising candidates because of their compatibility to integrated photonic structures and the ability to generate photons on demand with low multiphoton emission, near-unity entanglement fidelity and high indistinguishability. One limiting factor is the emission blinking of the resonance fluorescence. This reduces the efficiency and limits the scalability in quantum networks. The neutral biexciton is resonantly excited via two-photon excitation displaying such blinking behavior. By introducing an additional weak off-resonant excitation, the balance of free charges close to the quantum dot was controlled. This leads to a reduction of blinking caused by the intrinsic Coulomb blockade due to captured charges. This method increases the excitation efficiency by 30% while maintaining the fidelity of the entangled-photon pairs.