Quantum 2025 – scientific programme

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FRI: Friday Contributed Sessions

FRI 5: QIP Implementations: Solid-State Devices II

FRI 5.4: Talk

Friday, September 12, 2025, 11:30–11:45, ZHG006

Deterministic single-step fabrication of quantum dot-circular Bragg grating resonators with high process yield — •Avijit Barua¹, Kartik Gaur¹, Léo J. Roche¹, Suk In Park², Priyabrata Mudi¹, Sven Rodt¹, Jin-Dong Song², and Stephan Reitzenstein¹ — ¹Institut für Physik und Astronomie, Technische Universität Berlin (TUB), Berlin, Germany — ²Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea

The integration of quantum dot (QD) single-photon emitters into photonic structures is pivotal for the establishment of hybrid quantum networks. Here, we use the deterministic, single-step in-situ electron-beam lithography (i-EBL) for integrating QDs into circular Bragg grating (CBG) resonators with high accuracy and scalability. Notably, devices with two/three rings deliver photon extraction efficiencies comparable to structures with more rings, enabling faster fabrication, reduced device footprint, and compatibility with electrical contacting. To demonstrate scalability, we report on the fabrication of several hundred QD-CBG devices across multiple sessions and samples. The devices exhibit bright, narrow-linewidth single-photon emission with excellent optical quality. To evaluate QD placement accuracy, we perform cathodoluminescence mapping along with scanning electron microscopy, and the statistical analysis of these devices shows that our i-EBL concept allows for sub-40 nm alignment accuracy and >80% process yield across various CBG geometries. Our findings highlight a reliable route toward scalable, high-performance QD-based single-photon sources for future integration in hybrid quantum photonic networks.

Keywords: Semiconductor Quantum Dot; Circular Bragg gratings; In-situ Electron-beam lithography