A research team from the University of Science and Technology of China (USTC) has devised a superconducting quantum computing prototype called Zuchongzhi-3. The prototype works on 105 qubits and 182 couplers with a speed that is 1015 times faster than the fastest supercomputer currently available. What’s more, it is one million times faster than the latest results published by Google.
According to researchers, this achievement is a big step towards enhancing the performance of quantum computation.
Quantum supremacy is a pivotal milestone in quantum computing. It refers to the moment when a quantum computer can perform a calculation or solve a practically impossible problem for the world’s fastest classical supercomputers to complete within a reasonable timeframe.
In 2019, Google’s 53-qubit Sycamore processor took 200 seconds to complete a random circuit sampling task. Usually, the world’s fastest supercomputer would have taken about 10,000 years to complete that task.
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Next, in 2023, using more advanced classical algorithms, the team at USTC completed the same task within 14 seconds. For this, they used more than 1,400 A100 GPUs. With Frontier supercomputers’ larger memory, the task can be completed in just 1.6 seconds, overturning Google’s earlier claim of ‘quantum computational supremacy.
In 2020, the team achieved the first rigorously proven quantum supremacy by introducing the “Jiuzhang” photonic quantum computing prototype, which uses the optimal classical algorithm. Later, in 2021, the same task was achieved in a superconducting system using the Zuchongzhi-2 processor.
In 2023, the Jiuzhang-3 quantum processor demonstrated supremacy by performing tasks 10¹⁶ times faster than classical supercomputers. In October 2024, Google’s Sycamore, a 67-qubit quantum processor, surpassed classical supercomputers by nine orders of magnitude.
The USTC team then enhanced the Zuchongzhi-2 to develop Zuchongzhi-3, featuring 105 qubits and 182 couplers. It achieves a coherence time of 72 microseconds, a single-qubit gate fidelity of 99.90%, a two-qubit gate fidelity of 99.62%, and a readout fidelity of 99.13%. The longer coherence time allows for more complex operations and computations.
The team then evaluated its capabilities by conducting an 83-qubit, 32-layer random circuit sampling task. They were amazed that the computational speed surpassed that of the world’s most powerful supercomputer by 15 orders of magnitude. It also outperformed the latest results published by Google in October of last year by 6 orders of magnitude.
Following this milestone, the team is advancing research in quantum error correction, quantum entanglement, quantum simulation, quantum chemistry, and other areas.
Using this architecture, the team integrated surface code and researched quantum error correction with a distance-7 surface code. They plan to increase this distance to 9 and 11, allowing for larger integration and manipulation of quantum bits.
Their work is highly significant and widely acclaimed. A journal reviewer called it ‘benchmarking a new superconducting quantum computer with state-of-the-art performance’ and a ‘significant upgrade from the previous 66-qubit device (Zuchongzhi-2).’
Journal Reference:
- Dongxin Gao et al., Establishing a New Benchmark in Quantum Computational Advantage with 105-qubit Zuchongzhi 3.0 Processor, Physical Review Letters (2025). DOI: 10.1103/PhysRevLett.134.090601
