The development of large-scale superconducting quantum computing requires efficient in-situ control methods that allow high-fidelity operations at millikelvin temperatures. Superconducting circuits based on Josephson junctions offer a promising solution due to their high speed, low power dissipation, and cryogenic nature. Here, we report a superconducting quantum controller that enables direct chip-to-chip interconnection with qubits at 10 mK and high-fidelity, all-digital manipulation. Randomized benchmarking reveals a uniformly high average Clifford fidelity of 99.9% with leakage to high energy levels on the order of 10−4, and an estimated average gate operation energy of 0.121 fJ, demonstrating the potential to resolve the control bottleneck in superconducting quantum computing.
@article{arxiv.2604.05693,
title = {A plug-and-play superconducting quantum controller at millikelvin temperatures enables exceeding 99.9% average gate fidelity},
author = {Kuang Liu and Zhiyuan Wang and Xiaoliang He and Siqi Li and Hao Wu and Xiangyu Ren and Zhengqi Niu and Wangpeng Gao and Chenluo Zhang and Pei Huang and Yu Wu and Liliang Ying and Wei Peng and Jaw-Shen Tsai and Zhirong Lin},
journal= {arXiv preprint arXiv:2604.05693},
year = {2026}
}