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Practical Magic  /  AI

A superconducting digital to analog converter operates at 20 millikelvin to tune quantum bits directly inside the fridge.

Massive bundles of individual wires currently limit the size of quantum computers because they generate too much heat. This superconducting converter sits right next to the qubits and handles signals internally to save space and energy. Operating at temperatures colder than deep space allows the device to control hardware without disrupting delicate quantum states. This miniaturization solves one of the most significant physical bottlenecks for scaling processors to thousands of qubits. It moves the field from lab bench prototypes toward practical, integrated quantum chips.

Original Paper

Millikelvin digital-to-analog converter for superconducting quantum processors

Ruizi Hu, Zongyuan Li, Zhancheng Yao, Yufei Wu, Qiang Zhang, Yining Jiao, Quan Guan, Lijing Jin, Wangwei Lan, Chengyao Li, Lu Ma, Liyong Mao, Huijuan Zhan, Ze Zhan, Ran Gao, Lijuan Hu, Kannan Lu, Xizheng Ma, Tenghui Wang, Peng Xiang, Chunqing Deng, Shasha Zhu

arXiv  ·  2604.25303

Scaling superconducting quantum processors is increasingly constrained by the wiring, heat load, and calibration overhead associated with delivering high-resolution analog signals from room temperature to qubits at millikelvin temperature. Here we demonstrate a superconducting digital-to-analog converter (DAC) integrated with high-coherence fluxonium qubits in a multi-chip module architecture. The DACs generate persistent analog flux signals for tuning qubit parameters and are programmed determi