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In this paper, we give quantum algorithms for two fundamental computation problems: solving polynomial systems over finite fields and optimization where the arguments of the objective function and constraints take values from a finite field…

Symbolic Computation · Computer Science 2018-10-09 Yu-Ao Chen , Xiao-Shan Gao , Chun-Ming Yuan

We analyze the complexity of quantum state verification in the context of solving systems of linear equations of the form $A \vec x = \vec b$. We show that any quantum operation that verifies whether a given quantum state is within a…

Quantum Physics · Physics 2021-02-24 Rolando D. Somma , Yigit Subasi

We establish an improved classical algorithm for solving linear systems in a model analogous to the QRAM that is used by quantum linear solvers. Precisely, for the linear system $A\x = \b$, we show that there is a classical algorithm that…

Quantum Physics · Physics 2023-04-18 Changpeng Shao , Ashley Montanaro

We study variable time search, a form of quantum search where queries to different items take different time. Our first result is a new quantum algorithm that performs variable time search with complexity $O(\sqrt{T}\log n)$ where…

Quantum Physics · Physics 2023-08-04 Andris Ambainis , Martins Kokainis , Jevgēnijs Vihrovs

Quantum computation offers a promising alternative to classical computing methods in many areas of numerical science, with algorithms that make use of the unique way in which quantum computers store and manipulate data often achieving…

Quantum Physics · Physics 2022-07-19 Christopher D. Phillips , Vladimir I. Okhmatovski

Solving systems of linear equations is a fundamental problem, but it can be computationally intensive for classical algorithms in high dimensions. Existing quantum algorithms can achieve exponential speedups for the quantum linear system…

Quantum Physics · Physics 2025-11-27 Junhyung Lyle Kim , Nai-Hui Chia , Anastasios Kyrillidis

Period finding and phase estimation are fundamental in quantum computing. Prior work has established lower bounds on their success probabilities. Such quantum algorithms measure a state $|\hat\ell\rangle$ in an $n$-qubit computational…

Quantum Physics · Physics 2025-12-30 Malik Magdon-Ismail , Khai Dong

Can linear systems be solved faster than matrix multiplication? While there has been remarkable progress for the special cases of graph structured linear systems, in the general setting, the bit complexity of solving an $n \times n$ linear…

Data Structures and Algorithms · Computer Science 2021-01-08 Richard Peng , Santosh Vempala

Packing and covering linear programs (PC-LPs) form an important class of linear programs (LPs) across computer science, operations research, and optimization. In 1993, Luby and Nisan constructed an iterative algorithm for approximately…

Data Structures and Algorithms · Computer Science 2018-02-28 Zeyuan Allen-Zhu , Lorenzo Orecchia

The noisy binary linear problem (NBLP) is known as a computationally hard problem, and therefore, it offers primitives for post-quantum cryptography. An efficient quantum NBLP algorithm that exhibits a polynomial quantum sample and time…

Quantum Physics · Physics 2022-10-17 Wooyeong Song , Youngrong Lim , Kabgyun Jeong , Jinhyoung Lee , Jung Jun Park , M. S. Kim , Jeongho Bang

Many computational problems are subject to a quantum speed-up: one might find that a problem having an O(n^3)-time or O(n^2)-time classic algorithm can be solved by a known O(n^1.5)-time or O(n)-time quantum algorithm. The question…

Quantum Physics · Physics 2022-12-22 Harry Buhrman , Bruno Loff , Subhasree Patro , Florian Speelman

Quantum algorithms for solving linear systems of equations have generated excitement because of the potential speed-ups involved and the importance of solving linear equations in many applications. However, applying these algorithms can be…

Optimal quantum linear equation solvers provide complexity $O(\kappa\log(1/\epsilon))$, where $\kappa$ is the condition number and $\epsilon$ is the allowable error. The optimal solver using a discrete adiabatic approach [PRX Quantum 3,…

Quantum Physics · Physics 2026-04-28 Pedro C. S. Costa , Alexander M. Dalzell , Dong An , Dominic W. Berry

Quantum Annealing (QA) is a computational framework where a quantum system's continuous evolution is used to find the global minimum of an objective function over an unstructured search space. It can be seen as a general metaheuristic for…

Quantum Physics · Physics 2022-02-04 Arthur Braida , Simon Martiel , Ioan Todinca

In breakthrough work, Tardos (Oper. Res. '86) gave a proximity based framework for solving linear programming (LP) in time depending only on the constraint matrix in the bit complexity model. In Tardos's framework, one reduces solving the…

Optimization and Control · Mathematics 2020-09-11 Daniel Dadush , Bento Natura , László A. Végh

We propose quantum algorithms, purely quantum in nature, for calculating the determinant and inverse of an $(N-1)\times (N-1)$ matrix (depth is $O(N^2\log N)$) which is a simple modification of the algorithm for calculating the determinant…

Quantum Physics · Physics 2025-06-02 Alexander I. Zenchuk , Georgii A. Bochkin , Wentao Qi , Asutosh Kumar , Junde Wu

State-of-the-art noisy intermediate-scale quantum devices (NISQ), although imperfect, enable computational tasks that are manifestly beyond the capabilities of modern classical supercomputers. However, present quantum computations are…

Quantum algorithms for graph problems are considered, both in the adjacency matrix model and in an adjacency list-like array model. We give almost tight lower and upper bounds for the bounded error quantum query complexity of Connectivity,…

Quantum Physics · Physics 2016-12-30 Christoph Durr , Mark Heiligman , Peter Hoyer , Mehdi Mhalla

For two unknown mixed quantum states $\rho$ and $\sigma$ in an $N$-dimensional Hilbert space, computing their fidelity $F(\rho,\sigma)$ is a basic problem with many important applications in quantum computing and quantum information, for…

Quantum Physics · Physics 2023-01-04 Qisheng Wang , Zhicheng Zhang , Kean Chen , Ji Guan , Wang Fang , Junyi Liu , Mingsheng Ying

Linear Complementarity Problems (LCPs) with sufficient matrices form an important subclass of LCPs, and it remains a significant open question whether problems in this class can be solved in polynomial time. Kojima, Megiddo, Noma, and…

Optimization and Control · Mathematics 2026-05-12 Marianna E. -Nagy , László A. Végh