One million times. That is how much faster a Chinese superconducting quantum processor ran a benchmark task than Google’s latest published quantum result, according to the team that built it. Against the most powerful classical supercomputer, the gap is 15 orders of magnitude.
The machine is Zuchongzhi-3, from a research group at the University of Science and Technology of China (USTC), part of the Chinese Academy of Sciences. It has 105 qubits and 182 couplers. The study, led by Jianwei Pan, Xiaobo Zhu, Chengzhi Peng and colleagues, ran as a cover article in Physical Review Letters.
The specs
Zuchongzhi-3 builds on the 66-qubit Zuchongzhi-2. The team reports a coherence time of 72 microseconds, simultaneous single-qubit gate fidelity of 99.90%, two-qubit gate fidelity of 99.62% and readout fidelity of 99.13%. For the test, researchers ran an 83-qubit, 32-layer random circuit sampling task. They say it shows the strongest quantum computational advantage yet in a superconducting system.
The benchmark has a contested history. Google’s 53-qubit Sycamore processor completed a random circuit sampling task in 200 seconds in 2019, a job estimated to take 10,000 years on the best supercomputer then. In 2023, USTC researchers showed a classical algorithm could finish it in 14 seconds using more than 1,400 A100 GPUs. On the Frontier supercomputer, with its expanded memory, the same task now takes 1.6 seconds.
The USTC group has its own record. It claimed the first rigorously proven quantum supremacy with the Jiuzhang photonic prototype in 2020, followed by a superconducting demonstration on Zuchongzhi-2 in 2021. Its 255-photon Jiuzhang-3 followed in 2023.
What is next
The team says it is now working on quantum error correction, entanglement, simulation and quantum chemistry. It has adopted a 2D grid qubit architecture and is developing error correction with a distance-7 surface code, with plans to extend to distances of 9 and 11. One journal reviewer called the work a “significant upgrade” over the earlier 66-qubit device.
A separate Chinese result concerns memory. Origin Quantum, working with USTC and the Institute of Artificial Intelligence at the Hefei Comprehensive National Science Center, built a quantum routing system for bucket-brigade quantum random access memory, China’s Science and Technology Daily reported. Tested on the home-grown Origin Wukong computer, a single router reached up to 98% information transmission efficiency, and a two-layer routing network held 93%. Average fidelity in random-access benchmarks was 94.8% for one router and 82.4% for two layers. The findings appeared in Physical Review X.
Sources
- [News] Chinese Researchers Achieve Breakthrough in Superconducting Quantum Computer Architecture
- China's new quantum thermometer can measure extreme-low temperatures
- China’s New Quantum Machine Runs One Million Times Faster Than Google’s
