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arXiv · 2605.18124

Integrated time-bin entangled quantum light source on a 4H-SiC microring chip

Hong Zeng·Bing-Cheng Yang·Yun-Ru Fan·Li-Ping Zhou·Cheng-Li Wang·Bo-Wen Chen·Ai-Lun Yi·Yong Geng·Guang-Wei Deng·You Wang·Hai-Zhi Song·Jun-Tao Zhang·Hao Li·Li-Xing You·Zi-Hao Zhan·Kai Guo·Xin Ou·Guang-Can Guo·Qiang Zhou
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Abstract

Integrated time-bin-entangled photon-pair source with cavity-enhanced nonlinear optical processes is essential for quantum information technologies. However, microcavities with a high quality factor inherently introduce a trade-off between generation efficiency and photon bandwidth, which hinders the development of high-speed quantum networks with an integrated source. Here, we address this challenge by optimizing the nonlinearity property of the material and the geometry of the integrated microring resonator with a 4H-silicon carbide platform. Operating at a loaded quality factor of 1.9 $\times$ 10^5 - spectral bandwidth of 1.0 GHz and pumped with 300-ps double pulses separated by 1.25 ns at a repetition rate of 160 MHz, the device achieves a time-bin-entangled photon-pair generation rate of 1.35 $\times$ 10^7 s^-1 mW^-2. A raw visibility of 95.55 $\pm$ 0.18% is measured, showing a violation of Bell's inequality by more than 138 standard deviations, and a fidelity of 94.37 $\pm$ 0.22% is obtained by quantum state tomography. These results provide a scalable pathway to an efficient and broadband time-bin entangled quantum light source, overcoming intrinsic limitations of cavity-based designs and advancing integrated platforms for future quantum communication networks.

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Hong Zeng, Bing-Cheng Yang, Yun-Ru Fan, Li-Ping Zhou, Cheng-Li Wang, Bo-Wen Chen, Ai-Lun Yi, Yong Geng, Guang-Wei Deng, You Wang, Hai-Zhi Song, Jun-Tao Zhang, Hao Li, Li-Xing You, Zi-Hao Zhan, Kai Guo, Xin Ou, Guang-Can Guo, Qiang Zhou. 2026-05-18. Integrated time-bin entangled quantum light source on a 4H-SiC microring chip. https://arxiv.org/abs/2605.18124

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