[News] Chinese Researchers Achieve Breakthrough in Superconducting Quantum Computer Architecture

Researchers from Origin Quantum, in collaboration with the University of Science and Technology of China (USTC) and the Institute of Artificial Intelligence at the Hefei Comprehensive National Science Center, have developed a coherent quantum routing system for bucket-brigade Quantum Random Access Memory (QRAM), according to China’s Science and Technology Daily.

The system, deployed and validated on the home-grown superconducting quantum computer “Origin Wukong,” addresses a long-standing scalability bottleneck in QRAM design. The findings were recently published in the physics journal Physical Review X.

In quantum computing architectures, QRAM serves as a critical data storage and scheduling hub, enabling algorithms for quantum search and quantum machine learning. A central component of QRAM is the quantum router, which directs quantum information to target memory addresses based on input instructions.

Traditional quantum routing schemes, however, suffer from severe scalability limitations. As the routing network expands, each additional node requires a large number of standard quantum gates to decompose routing instructions. This significantly increases circuit depth and accumulates operational errors, constraining the expansion of QRAM.

To overcome this challenge, the research team proposed a quantum router architecture leveraging auxiliary energy levels in superconducting qubits.

The “coherent quantum routing system” utilizes these auxiliary energy levels to convert complex controlled-SWAP operations into shallow-depth equivalent circuits composed of a minimal number of two-qubit transition gates. By bypassing redundant nodes, this approach significantly reduces circuit depth and mitigates error rates.

The researchers experimentally constructed three independent quantum routers and a two-layer quantum routing network on “Origin Wukong” for performance evaluation.

Test results demonstrated that the single quantum router achieved an information transmission efficiency of up to 98%, while the two-layer routing network maintained an overall efficiency of 93%. In random-access benchmarks, the average fidelity reached 94.8% for a single router and 82.4% for the two-layer network.

The experimental data indicates that the proposed scheme achieves coherent, reversible routing controlled by quantum addresses, demonstrating strong potential for scaling up to larger quantum networks.

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