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HL: Fachverband Halbleiterphysik
HL 17: Materials and devices for quantum technology I
HL 17.9: Vortrag
Montag, 16. März 2020, 17:30–17:45, POT 112
Optical characterization of deterministically fabricated quantum-dot microlenses on (111)B GaAs substrate — •Martin von Helversen1, Alexey Haisler2, Sarah Fischbach1, Dimitry Dimitriev2, Sven Rodt1, Vladimir Haisler2, Ilya Derebezov2, and Stephan Reitzenstein1 — 1Institute of Solid State Physics, Technische Universität Berlin, 10623 Berlin, Germany — 2Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
Entangled photon-pairs are excellent candidates for the implementation of secure quantum key distribution schemes [1]. Among suitable single-photon emitters semiconductor quantum dots (QDs) are promising due to their ability to emit polarization entangled photon-pairs on demand via the radiative biexciton-exciton cascade [2]. This, however, requires QDs with a vanishing fine-structure-splitting (FSS) of the excitonic state. We report on QDs grown via molecular beam epitaxy on (111)B GaAs substrate, where the piezoelectric field is directed along the growth direction and allows for a more symmetric growth compared to QDs on (100)-substrate. We find a reduced FSS of 13 ± 2 µeV compared to (100) QDs with reported values of around 30 µeV [3]. By further integation of these emitters into deterministic microlenses [4], their outcoupling efficiency can be optimized to values of above 40%.
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[4] Gschrey, M. et al., Nat. Commun. 6, 7662 (2015).