发表机构
Quantinuum（Quantinuum）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在Quantinuum H2量子计算机上发现，对于紧束缚链基态制备，绝热演化虽动量分辨率较低但噪声更小，优于高精度的费米子傅里叶变换，并提出了更廉价低噪的动量测量方案，强调降低噪声敏感性的重要性。
AI 中文摘要
量子算法通常以门数量或电路深度为优化目标。我们在Quantinuum System Model H2量子计算机上发现，对于紧束缚链基态制备，存在一个系统尺寸$N$，超过该尺寸后，绝热演化在相同门数量和相同电路深度下能达到比费米子傅里叶变换（FFT）显著更低的能量。我们将FFT的高噪声敏感性归因于其高精度，即能够以$1/N$的分辨率区分动量。动量空间中的这种高分辨率要求实空间中的长程耦合，这会更快地传播误差。相比之下，尽管绝热演化等局域物理电路具有较粗的动量分辨率，但它们传播误差也更慢。对于物理应用，高动量分辨率很少是必需的，通常值得以降低噪声敏感性为代价来换取。我们还引入了一种动量测量方案，虽然不如FFT精确，但成本更低且噪声更小。我们表明，在Quantinuum System Model H2量子计算机上，该方案在谱函数测量方面比FFT取得了更好的性能。我们的工作强调了降低量子算法噪声敏感性的重要性，这超越了门数量或电路深度的考量。
英文摘要
Quantum algorithms are usually optimized for gate count or circuit depth. We find on Quantinuum System Model H2 quantum computer that for a tight-binding chain ground state preparation, there is a system size $N$ beyond which the adiabatic evolution reaches significantly lower energies than the Fermionic Fourier Transform (FFT), with the same number of gates, and with the same circuit depth. We attribute this high noise sensitivity of the FFT to its high precision, being able to distinguish momenta by $1/N$. This high resolution in momentum space requires long-range couplings in real space, which propagates errors faster. In contrast, although local and physical circuits such as the adiabatic evolution have a coarser momentum resolution, they also propagate errors more slowly. For physical applications, high momentum resolution is rarely required and is often worth trading for low noise sensitivity. We also introduce a momentum measurement scheme that although less precise than FFT, is less costly and less noisy. We show that it achieves better performance than FFT for spectral function measurement on Quantinuum System Model H2 quantum computer. Our work emphasizes the importance of reducing the noise sensitivity of quantum algorithms, beyond the number of gates or circuit depth.
Comments15 pages
