Quantum router achieves 98% efficiency in China’s Wukong computer

Summary

Chinese research teams demonstrated a consistent quantum routing system on the Origin Wukong superconducting quantum computer. Transmission efficiency reached 98% in a single router and 93% in a two-layer network. The study aims to enable scalable bucket-brigade quantum random-access memory (QRAM).

Why it matters

Quantum memory is one of the critical bottlenecks preventing quantum computers from scaling beyond a few hundred qubits. Therefore, a reliable routing architecture in real superconducting hardware is a significant step. The work also signals a shift in China's quantum program: moving from isolated component benchmarks to testing multi-stage quantum functions in actual machines. The core engineering challenge lies precisely in this transition.

Highlights

• Transmission efficiency reached 98% in a single router and 93% in a two-layer network
• Random access fidelity was measured at 94.8% (single router) and 82.4% (two-layer network)
• Experiments were conducted on Origin Wukong, China's third-generation superconducting platform, using three independent routers

Critical take

The 98% figure in the headline refers to a single routing component, not the full memory system. When the second layer is added, fidelity drops to 82.4%, which is still well below the threshold required for fault-tolerant quantum computing. Moreover, the results were reported in Science and Technology Daily, a state-affiliated publication; independent peer-reviewed replication is still pending.