MilestoneQuantum advantageDisputed
Chinese team claims quantum advantage with Jiuzhang, a machine that uses light
Dec 3, 2020
Researchers at the University of Science and Technology of China (USTC) report that Jiuzhang, which computes with particles of light (photons), ran a task called Gaussian boson sampling at a rate they estimate is about 100 trillion times faster than supercomputers could.
Why it matters
It followed Google's 2019 Sycamore claim with a completely different technology, light instead of superconducting circuits, but whether it truly beat classical computers is still debated.
Google researchers later reported classical algorithms that score better than the experiment on the statistical tests it used as evidence (arXiv 2109.11525), so the advantage claim is contested.
Jian-Wei Pan · Chao-Yang Lu · USTC
Related
Sources (4)
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arXiv (Zhong et al.)
Quantum computational advantage using photons
“We observe up to 76 output photon-clicks, which yield an output state space dimension of $10^{30}$ and a sampling rate that is $10^{14}$ faster than using the state-of-the-art simulation strategy and supercomputers.”
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Science
Quantum computational advantage using photons
“Quantum computational advantage using photons”
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Nature (News)
Physicists in China challenge Google's 'quantum advantage'
“A team in China claims to have made the first definitive demonstration of 'quantum advantage' — exploiting the counter-intuitive workings of quantum mechanics to perform computations that would be prohibitively slow on classical computers.”
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arXiv (Villalonga et al., Google)
Efficient approximation of experimental Gaussian boson sampling
“Here we give classical sampling algorithms with better total variation distance and Kullback-Leibler divergence than these experiments and a computational cost quadratic in the number of modes.”
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