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

Millikelvin digital-to-analog converter for superconducting quantum processors

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Abstract

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 deterministically using single-flux-quantum (SFQ) pulses, providing a digital interface compatible with established SFQ routing and demultiplexing technologies. Operating at millikelvin temperature, the DACs enable in-situ tuning of fluxonium qubits without measurable degradation of qubit coherence. The presented device provides a static control primitive for flux-tunable qubits, enabling parameter homogenization and eliminating the need for individual room-temperature DC bias lines. These results establish SFQ-programmable millikelvin DACs as a building block for digitally controlled superconducting quantum processors.

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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. 2026-04-28. Millikelvin digital-to-analog converter for superconducting quantum processors. https://arxiv.org/abs/2604.25303

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