Statistical limits for quantum networks with semiconductor entangled photon sources

Jingzhong Yang, Michael Zopf, Pengji Li, Nand Lal Sharma, Weijie Nie, Frederik Benthin, Tom Fandrich, Eddy Patrick Rugeramigabo, Caspar Hopfmann, Robert Keil, Oliver G. Schmidt, Fei Ding
Phys. Rev. B 105, 235305 (2022)

Semiconductor quantum dots are promising building blocks for quantum communication applications. Although deterministic, efficient, and coherent emission of entangled photons has been realized, implementing a practical quantum repeater remains outstanding. Here we explore the statistical limits for entanglement swapping with sources of polarization-entangled photons from the commonly used biexciton-exciton cascade. We stress the necessity of tuning the exciton fine structure, and explain why the often observed time evolution of photonic entanglement in quantum dots is not applicable for large quantum networks. We identify the critical, statistically distributed device parameters for entanglement swapping based on two sources. A numerical model for benchmarking the consequences of device fabrication, dynamic tuning techniques, and statistical effects is developed, in order to bring the realization of semiconductor-based quantum networks one step closer to reality.