论文标题
多状态交换测试算法
Multi-state Swap Test Algorithm
论文作者
论文摘要
估计两个状态之间的重叠是量子信息中多个应用程序的重要任务。但是，典型的交换测试电路一次只能测量一对唯一的量子状态。在这项研究中，我们设计了一个递归量子电路来测量多个量子状态的重叠$ | ϕ_1 ... ϕ_n \ rangle $与$ O（n \ log n）$ Conloted-SWAP（CSWAP）GATES（CSWAP）和$ O（\ log log n）$ n n）$ nathilary qunbits同时同时使用。该电路使我们能够在输入量子状态之间获得所有成对重叠，$ | \ langledarge_i | ϕ_j \ rangle |^2 $。与测量多个量子状态重叠的现有方案相比，我们的方案提供了更高的精度和更少的辅助量子量的消耗。此外，我们在IBM量子云平台上进行了仿真实验，以验证该方案的优势。
Estimating the overlap between two states is an important task with several applications in quantum information. However, the typical swap test circuit can only measure a sole pair of quantum states at a time. In this study we designed a recursive quantum circuit to measure overlaps of multiple quantum states $|ϕ_1...ϕ_n\rangle$ concurrently with $O(n\log n)$ controlled-swap (CSWAP) gates and $O(\log n)$ ancillary qubits. This circuit enables us to get all pairwise overlaps among input quantum states $|\langleϕ_i|ϕ_j\rangle|^2$. Compared with existing schemes for measuring the overlap of multiple quantum states, our scheme provides higher precision and less consumption of ancillary qubits. In addition, we performed simulation experiments on IBM quantum cloud platform to verify the superiority of the scheme.
