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arXiv · 2511.22920

CO-QLink: Cryogenic Optical Link for Scalable Quantum Computing Systems and High-Performance Cryogenic Computing Systems

Zheng Chang·Siqi Zhang·Wenqiang Huang·Tian Tian·Qichun Liu·Tiefu Li·Nan Qi·Yuanjin Zheng·Zhihua Wang·Yanshu Guo·Hanjun Jiang
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Abstract

Cryogenic systems necessitate extensive data transmission between room-temperature and cryogenic environments, as well as within the cryogenic temperature domain. High-speed, low-power data transmission is pivotal to enabling the deployment of larger-scale cryogenic systems, including the scalable quantum computing systems and the high-performance cryogenic computing systems fully immersed in liquid nitrogen. In contrast to wireline and microwave links, optical communication links are emerging as a solution characterized by high data rates, high energy efficiency, low signal attenuation, absence of thermal conduction, and superior scalability. In this work, a 4K heat-insulated high-speed (56Gbps) low-power (1.6pJ/b) transceiver (TRX) that achieves a complete link between 4K systems and room temperature (RT) equipment is presented. Copackaged with a PIN photodiode (PD), the RX uses an inverter-based analog front-end and an analog half-rate clock data recovery loop. Connecting to a Mach-Zehnder modulator (MZM), the TX contains a voltage-mode driver with current-mode injection for low-power output-swing-boosting and 3-tap feed-forward equalization (FFE). This link has been demonstrated in the control and readout of a complete superconducting quantum computing system.

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Zheng Chang, Siqi Zhang, Wenqiang Huang, Tian Tian, Qichun Liu, Tiefu Li, Nan Qi, Yuanjin Zheng, Zhihua Wang, Yanshu Guo, Hanjun Jiang. 2025-11-28. CO-QLink: Cryogenic Optical Link for Scalable Quantum Computing Systems and High-Performance Cryogenic Computing Systems. https://arxiv.org/abs/2511.22920

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