Regensburg 2022 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 8: Quantum Dots and Wires 2: Optics 1

HL 8.6: Talk

Monday, September 5, 2022, 17:00–17:15, H32

Franson interference on a resonantly driven biexciton cascade — •Marcel Hohn¹, Kisa Barkemeyer², Matthias Kunz¹, Arsenty Kaganskiy¹, Samir Bounouar¹, Alexander Carmele², Sven Rodt¹, and Stephan Reitzenstein¹ — ¹Institut für Festkörper Physik, Technische Universität Berlin, 10623 Berlin, Germany — ²Institut für Theoretische Physik, Technische Unviersität Berlin, 10623 Berlin, Germany

The deterministic generation of entangled photon pairs is of special interest for applications in quantum communication and computation. As many experiments focus on entanglement in the polarization base, energy-time entangled photons used for Franson interference offer the advantage of high robustness in long-distance fiber transmission. We report on Franson measurements performed in cw mode on the resonantly driven biexciton cascade of a deterministically fabricated quantum dot device. The two-photon visibility of such a three-level system crucially dependents on the decay rates of the ideally long upper- and short living intermediate state [1]. A relation hard to achieve for the biexciton cascade, where the lifetime of the biexciton state is usually short compared to the exciton state. Nevertheless, our measurements yield a high two-photon visibility up to (73 ± 2)%, surpassing the CHSH inequality of 70.7% [2]. This result demonstrates the high potential of generating energy time entangled photons in a resonantly driven biexciton cascade.

[1] K. Barkemeyer, et al., Phys. Rev. A, 103, 62423 (2021)

[2] J. F. Clauser, et al., Phys. Rev. Lett. 23, 880 (1969)