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arXiv · 2502.09367

Deterministic fabrication of GaAs-quantum-dot micropillar single-photon sources

Abdulmalik A. Madigawa·Martin Arentoft Jacobsen·Claudia Piccinini·Paweł Wyborski·Ailton Garcia Jr.·Saimon F. Covre da Silva·Armando Rastelli·Battulga Munkhbat·Niels Gregersen
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Abstract

This study investigates the performance of droplet-etched GaAs quantum dots (QDs) integrated into micropillar structures using a deterministic fabrication technique. We demonstrate a unity QD positioning yield across 74 devices and consistent device performance. Under p-shell excitation, the QD decay dynamics within the micropillars exhibit biexponential behavior, accompanied by intensity fluctuations limiting the source efficiency to < 4.5%. Charge stabilization via low-power above-band LED excitation effectively reduces these fluctuations, doubling the source efficiency to $\sim$ 9%. Moreover, we introduce suppression of radiation modes by introducing cylindrical rings theoretically predicted to boost the collection efficiency by a factor of 4. Experimentally, only a modest improvement is obtained, underscoring the influence of even minor fabrication imperfections for this advanced design. Our findings demonstrate the reliability of our deterministic fabrication approach in producing high-yield, uniform devices, while offering detailed insights into the influence of charge noise and complex relaxation dynamics on the performance.

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Abdulmalik A. Madigawa, Martin Arentoft Jacobsen, Claudia Piccinini, Paweł Wyborski, Ailton Garcia Jr., Saimon F. Covre da Silva, Armando Rastelli, Battulga Munkhbat, Niels Gregersen. 2025-02-13. Deterministic fabrication of GaAs-quantum-dot micropillar single-photon sources. https://doi.org/10.1002/qute.202500128

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