论文标题
双频量子相估计减轻量子算法的光谱泄漏
Dual-Frequency Quantum Phase Estimation Mitigates the Spectral Leakage of Quantum Algorithms
论文作者
论文摘要
量子相估计是各种量子算法中的重要组成部分。但是，当记录长度的倒数不是未知阶段的整数倍数时，它会遭受光谱泄漏的损失，这会导致精度降解。对于现有的单样本估计方案，已经提出了基于窗口的方法来缓解光谱泄漏。随着进一步的进步，我们提出了一个双频估计器，当有多个样品可用时，该估计器渐近地接近Cramer-Rao结合。数值结果表明，当样本数量足够高时，所提出的估计器的表现优于现有的基于窗口的方法。
Quantum phase estimation is an important component in diverse quantum algorithms. However, it suffers from spectral leakage, when the reciprocal of the record length is not an integer multiple of the unknown phase, which incurs an accuracy degradation. For the existing single-sample estimation scheme, window-based methods have been proposed for spectral leakage mitigation. As a further advance, we propose a dual-frequency estimator, which asymptotically approaches the Cramer-Rao bound, when multiple samples are available. Numerical results show that the proposed estimator outperforms the existing window-based methods, when the number of samples is sufficiently high.
