关于量子相位估计的低深度算法
On low-depth algorithms for quantum phase estimation
AI总结：
针对早期容错量子器件对量子相位估计算法的多维度需求，本文证明现有量子计量学算法可满足前三项要求，并提出改进版算法满足全部四项要求，适配早期容错量子器件场景。
摘要：
量子相位估计是量子计算的关键组成部分之一。对于早期容错量子器件，理想的量子相位估计算法需满足以下条件：（1）使用最少数量的辅助量子比特；（2）可适配存在显著失配的非精确初态；（3）总资源使用达到海森堡极限；（4）当初态与目标态的重叠度趋近于1时，最大电路长度的前置因子逐渐减小。本文证明，量子计量学中的一种现有算法可满足前三项要求。作为第二项贡献，我们提出了该算法的一种改进版本，它还能满足第四项要求，这使其对早期容错量子器件尤其具有吸引力。
英文摘要：
Quantum phase estimation is one of the critical building blocks of quantum computing. For early fault-tolerant quantum devices, it is desirable for a quantum phase estimation algorithm to (1) use a minimal number of ancilla qubits, (2) allow for inexact initial states with a significant mismatch, (3) achieve the Heisenberg limit for the total resource used, and (4) have a diminishing prefactor for the maximum circuit length when the overlap between the initial state and the target state approaches one. In this paper, we prove that an existing algorithm from quantum metrology can achieve the first three requirements. As a second contribution, we propose a modified version of the algorithm that also meets the fourth requirement, which makes it particularly attractive for early fault-tolerant quantum devices.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
