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arXiv · 2409.08982

A Fiber-pigtailed Quantum Dot Device Generating Indistinguishable Photons at GHz Clock-rates

Lucas Rickert·Kinga Żołnacz·Daniel A. Vajner·Martin von Helversen·Sven Rodt·Stephan Reitzenstein·Hanqing Liu·Shulun Li·Haiqiao Ni·Paweł Wyborski·Grzegorz Sęk·Anna Musiał·Zhichuan Niu·Tobias Heindel
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Abstract

Solid-state quantum light sources based on semiconductor quantum dots (QDs) are increasingly employed in photonic quantum information applications. Especially when moving towards real-world scenarios outside shielded lab environments, the efficient and robust coupling of nanophotonic devices to single-mode optical fibers offers substantial advantage by enabling "plug-and-play" operation. In this work we present a fiber-pigtailed cavity-enhanced source of flying qubits emitting single indistinguishable photons at clock-rates exceeding $1\,$GHz. This is achieved by employing a fully deterministic technique for fiber-pigtailing optimized QD-devices based on hybrid circular Bragg grating (hCBG) micro-cavities. The fabricated fiber-pigtailed hCBGs feature radiative emission lifetimes of $<80\,$ps, corresponding to a Purcell factor of $\sim$9, a suppression of multi-photon emission events with $g^{(2)}(0)<1\%$, a photon-indistinguishability $>80\%$ and a measured single-photon coupling efficiency of 53$\%$ in a high numerical aperture single-mode fiber, corresponding to 1.2 Megaclicks per second at the single-photon detectors under $80\,$MHz excitation clock-rates. Furthermore, we show that high multi-photon suppression and indistinguishability prevail for excitation clock-rates exceeding $1\,$GHz. Our results show that Purcell-enhanced fiber-pigtailed quantum light sources based on hCBG cavities are a prime candidate for applications of quantum information science.

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Lucas Rickert, Kinga Żołnacz, Daniel A. Vajner, Martin von Helversen, Sven Rodt, Stephan Reitzenstein, Hanqing Liu, Shulun Li, Haiqiao Ni, Paweł Wyborski, Grzegorz Sęk, Anna Musiał, Zhichuan Niu, Tobias Heindel. 2024-09-13. A Fiber-pigtailed Quantum Dot Device Generating Indistinguishable Photons at GHz Clock-rates. https://doi.org/10.1515/nanoph-2024-0519

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