Quantum computers will be able solve important problems with significant polynomial and exponential speedups over their classical counterparts, for instance in option pricing in finance, and in real-space molecular chemistry simulations. However, key applications can only achieve their potential speedup if their inputs are prepared efficiently. We effectively solve the important problem of efficiently preparing quantum states following arbitrary continuous (as well as more general) functions with complexity logarithmic in the desired resolution, and with rigorous error bounds. This is enabled by the development of a fundamental subroutine based off of the simulation of rank-1 projectors. Combined with diverse techniques from quantum information processing, this subroutine enables us to present a broad set of tools for solving practical tasks, such as state preparation, numerical integration of Lipschitz continuous functions, and superior sampling from probability density functions. As a result, our work has significant implications in a wide range of applications, for instance in financial forecasting, and in quantum simulation.
Linear-depth quantum oracles for clique problems from edge colorings and graph states, with linear non-Clifford cost and a provably bounded-error k-clique search
School of Electrical and Computer Engineering, College of Engineering, University of Tehran（德黑兰大学工程学院电气与计算机工程学院）
Scalable Multi-QPU Circuit Design for Dicke State Preparation: Optimizing Communication Complexity and Local Circuit Costs
Institute of Computing Technology, Chinese Academy of Sciences（中国科学院计算技术研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Shandong University（山东大学）
准备给定哈密顿量的基态并估计其基态能量是重要的但计算困难的任务。然而，如果有一些额外的信息，这些问题可以在量子计算机上有效地解决。我们假设可以有效地制备与基态具有非平凡重叠的初始态，并且基态能量和第一激发能之间的光谱间隙从下面被限制。有了这些假设，我们设计了一个算法，准备的基态时，地面能量的上限是已知的，其运行时间有一个对数依赖于逆误差。当这样的上限未知时，我们提出了一种混合量子经典算法来估计基态能量，其中与[Ge et al. 2019]中提出的当前最先进的算法相比，查询数量对初始状态对所需精度的依赖性呈指数级改善。这两种算法可以结合起来准备一个基态，而不需要知道基态能量的上限。我们还将其应用于非结构化搜索问题和量子近似计数问题，证明了我们的算法达到了复杂度下限。
Quantum state preparation of spin eigenstates including the Dicke states with generalized all-coupled interaction in a spintronic quantum computing architecture
Quantum-Amplified M/G/1/K Simulation: A Comparator-Controlled Framework for Arbitrary Service Distributions
School of Industrial Engineering and Management, Shenkar – Engineering. Design. Art（申卡拉工程、设计与艺术学院工业工程与管理学院）；School of Industrial Engineering and Management, Afeka Tel Aviv Academic College of Engineering（阿费卡特拉维夫理工学院工业工程与管理学院）
C. N. Yang Institute for Theoretical Physics and Department of Physics and Astronomy, State University of New York at Stony Brook（纽约州立大学石溪分校杨振宁理论物理研究所及物理与天文学系）
Solving the Lipkin model using quantum computers with two qubits only with a hybrid quantum-classical technique based on the Generator Coordinate Method
Space-bounded quantum state testing via space-efficient quantum singular value transformation
Graduate School of Mathematics, Nagoya University（名古屋大学大学院数学研究科）；School of Computer and Communication Sciences, École Polytechnique Fédérale de Lausanne（洛桑联邦理工学院计算机与通信科学学院）；School of Computer Science, Shanghai Jiao Tong University（上海交通大学计算机学院）
