Regensburg 2019 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 33: Quantum light sources

HL 33.8: Vortrag

Mittwoch, 3. April 2019, 17:00–17:15, H34

Impact of the excitonic spin dynamics on the entanglement from a InGaAs quantum dot — •Samir Bounouar¹, Gabriel Rein¹, Julian Schleibner², Alexander Carmele², Peter Schnauber¹, Andre Strittmatter^1,3, Sven Rodt¹, and Stephan Reitzenstein¹ — ¹Institut für Festkörperphysik, Technische Universität Berlin, Berlin, Germany — ²Institut für Theoretische Physik, Technische Universität Berlin, Berlin, Germany — ³Abteilung für Halbleiterepitaxie, Otto-von-Guericke, Universität, Magdeburg, Germany

Maximal entanglement is an important resource in photonic quantum technology and can be in principal generated by a semiconductor quantum dot even in the presence of finite fine structure splitting [1]. However, the exciton spin dynamics constitutes an important obstacle to perfect entanglement. We report on photon-correlation experiments performed on single InGaAs quantum dots integrated deterministically into monolithic microlenses. Non-phonon-mediated spin decoherence processes are systematically investigated and their influence on the quality of the generated entanglement by quantum dots is evaluated. In particular, exchange interaction, decoherence and nuclear spin induced precessions are evidenced through a series of tomography measurements on a large number of single quantum dots. A drop of the entanglement due to these processes is evidenced for small excitonic fine structure splittings and is discussed by a theoretical model introducing exchange interaction.

[1] S. Bounouar et al., Applied Physics Letters 112, 153107 (2018)