论文标题
量子幅度估计的低深度算法
Low depth algorithms for quantum amplitude estimation
论文作者
论文摘要
我们设计和分析了两种新的低深度算法,用于振幅估计(AE),以实现量子加速和电路深度之间的最佳权衡。 For $β\in (0,1]$, our algorithms require $N= \tilde{O}( \frac{1}{ ε^{1+β}})$ oracle calls and require the oracle to be called sequentially $D= O( \frac{1}{ ε^{1-β}})$ times to perform amplitude estimation within additive error $ε$。 第一种算法(Power Law AE)使用Suzuki等人\ cite {S20}引入的框架中的权力法时间表。 The algorithm works for $β\in (0,1]$ and has provable correctness guarantees when the log-likelihood function satisfies regularity conditions required for the Bernstein Von-Mises theorem. The second algorithm (QoPrime AE) uses the Chinese remainder theorem for combining lower depth estimates to achieve higher accuracy. The algorithm works for discrete $β=q/k$ where $k \geq 2 $是该算法使用的不同型号模量和$ 1 \ leq Q \ leq k-1 $,并且具有完全严格的正确性证明,我们分析了两个算法在去极化噪声的情况下,并提供了与艺术幅度估计算法的数值比较。
We design and analyze two new low depth algorithms for amplitude estimation (AE) achieving an optimal tradeoff between the quantum speedup and circuit depth. For $β\in (0,1]$, our algorithms require $N= \tilde{O}( \frac{1}{ ε^{1+β}})$ oracle calls and require the oracle to be called sequentially $D= O( \frac{1}{ ε^{1-β}})$ times to perform amplitude estimation within additive error $ε$. These algorithms interpolate between the classical algorithm $(β=1)$ and the standard quantum algorithm ($β=0$) and achieve a tradeoff $ND= O(1/ε^{2})$. These algorithms bring quantum speedups for Monte Carlo methods closer to realization, as they can provide speedups with shallower circuits. The first algorithm (Power law AE) uses power law schedules in the framework introduced by Suzuki et al \cite{S20}. The algorithm works for $β\in (0,1]$ and has provable correctness guarantees when the log-likelihood function satisfies regularity conditions required for the Bernstein Von-Mises theorem. The second algorithm (QoPrime AE) uses the Chinese remainder theorem for combining lower depth estimates to achieve higher accuracy. The algorithm works for discrete $β=q/k$ where $k \geq 2$ is the number of distinct coprime moduli used by the algorithm and $1 \leq q \leq k-1$, and has a fully rigorous correctness proof. We analyze both algorithms in the presence of depolarizing noise and provide numerical comparisons with the state of the art amplitude estimation algorithms.