AI 中文总结
研究量子误差缓解基准测试中零噪声外推的失效模式，当噪声放大超出可用信号时会产生虚假改进。通过真实硬件测量证实，引入匹配成本负控制和零成本检查标志，提炼出ZNE基准测试报告清单。
AI 中文摘要
可靠的量子误差缓解（QEM）基准测试需要区分后处理算法中的真实改进和人为因素。本文揭示了理查森零噪声外推（ZNE）中的一种失效模式，这是一种在基准测试和实验中经常（且常隐含）依赖的广泛使用的技术。当噪声放大超出可用信号时，外推不再反映基础物理，而是退化为对单个噪声测量的固定缩放，产生虚假的明显改进。在真实硬件（IQM Euro-Q-Exa）上的测量证实了仅普通折叠就会导致这种崩溃。我们还引入了匹配成本的“垃圾折叠”负控制，以及零成本检查标志，将两者提炼成ZNE基准测试的简短报告清单。
英文摘要
Reliable benchmarking of Quantum Error Mitigation (QEM) requires distinguishing genuine improvements from artefacts of the post-processing arithmetic. In this paper, we expose a failure mode in Richardson Zero-Noise Extrapolation (ZNE), a widely used technique routinely (and often implicitly) relied upon in benchmarks and experiments. When noise amplification operates beyond usable signals - a regime that is quickly reached on current hardware for non-trivial circuits - we show that the extrapolation no longer reflects the underlying physics, but collapses into a fixed rescaling of a single noisy measurement, producing a bogus apparent improvement that is independent of noise amplification. This poses a rarely considered threat to the validity of many empirical evaluations in quantum computing. Measurements on real hardware (IQM Euro-Q-Exa) confirm this collapse with ordinary folding alone: as circuit depth erodes the signal, the reported estimate decouples from the truth and overshoots the ideal by up to 21%. We further introduce a matched-cost "garbage-folding" negative control that carries no usable signal yet reports a larger apparent improvement than genuine folding - showing that the magnitude of an improvement is not evidence of its correctness - alongside a zero-cost check flagging the artefact from data a benchmark already holds. We distil both into a short reporting checklist for ZNE benchmarks.
Comments4 pages including references, 2 Figures, Accepted for publication at IEEE Quantum Week (QCE) 2026
