In December 2025, USTC (University of Science and Technology of China) published results in Physical Review Letters for Zuchongzhi 3.2, a 107-physical-qubit superconducting processor. The system achieved below-threshold quantum error correction — the first non-US demonstration of this critical milestone, following Google Willow's achievement a year earlier.

Using a distance-7 surface code, Zuchongzhi 3.2 achieved an error suppression factor Λ=1.40 (vs Google Willow's Λ=2.14). The system deployed an innovative all-microwave quantum state leakage suppression architecture — independent of previous US architectures — achieving 72× leakage suppression (6.4×10⁻⁴).

Zuchongzhi 3.2 follows Zuchongzhi 3.0's earlier record (March 2025): 83-qubit 32-cycle RCS showed a 10¹⁵× speed advantage over Frontier with 2Q gate fidelity of 99.62%. Together, these results confirm that China's superconducting quantum program has reached parity with the global frontier in both quantum supremacy and fault-tolerant error correction research.

Source: https://quantumcomputingreport.com/ustcs-zuchongzhi-3-2-achieves-below-threshold-qec-milestone/