English
Related papers

Related papers: Optimal quantum spatial search with one-dimensiona…

200 papers

While the quantum query complexity of $k$-distinctness is known to be $O\left(n^{3/4-1/4(2^k-1)}\right)$ for any constant $k \geq 4$, the best previous upper bound on the time complexity was $\widetilde{O}\left(n^{1-1/k}\right)$. We give a…

Quantum Physics · Physics 2025-03-05 Stacey Jeffery , Sebastian Zur

Continuous time quantum walks provide an important framework for designing new algorithms and modelling quantum transport and state transfer problems. Often, the graph representing the structure of a problem contains certain symmetries that…

Quantum Physics · Physics 2015-11-03 Leonardo Novo , Shantanav Chakraborty , Masoud Mohseni , Hartmut Neven , Yasser Omar

The optimal runtime of a quantum computer searching a database is typically cited as the square root of the number of items in the database, which is famously achieved by Grover's algorithm. With parallel oracles, however, it is possible to…

Quantum random walks on graphs have been shown to display many interesting properties, including exponentially fast hitting times when compared with their classical counterparts. However, it is still unclear how to use these novel…

Quantum Physics · Physics 2009-11-07 Neil Shenvi , Julia Kempe , K. Birgitta Whaley

We provide several quantum algorithms for continuous optimization that do not require gradient estimation. Instead, we encode the optimization problem into the dynamics of a physical system and coherently simulate the time evolution. We…

Quantum Physics · Physics 2026-03-18 Ahmet Burak Catli , Sophia Simon , Nathan Wiebe

We study the kinetics for the search of an immobile target by randomly moving searchers that detect it only upon encounter. The searchers perform intermittent random walks on a one-dimensional lattice. Each searcher can step on a nearest…

Statistical Mechanics · Physics 2015-05-14 Gleb Oshanin , Katja Lindenberg , Horacio S Wio , Sergei Burlatsky

Quantum robots are described as mobile quantum computers and ancillary systems that move in and interact with arbitrary environments. Their dynamics is given as tasks which consist of sequences of alternating computation and action phases.…

Quantum Physics · Physics 2007-05-23 Paul Benioff

We study quantum algorithms for several fundamental string problems, including Longest Common Substring, Lexicographically Minimal String Rotation, and Longest Square Substring. These problems have been widely studied in the stringology…

Data Structures and Algorithms · Computer Science 2021-10-22 Shyan Akmal , Ce Jin

Quantum walks are a powerful framework for the development of quantum algorithms, with lackadaisical quantum walks (LQWs) standing out as an efficient model for spatial search. In this work, we investigate how broken-link decoherence…

Spatial search is an important problem in quantum computation, which aims to find a marked vertex on a graph. We propose a novel approach for designing deterministic quantum search algorithms on a variety of graphs via alternating quantum…

Quantum Physics · Physics 2023-08-25 Qingwen Wang , Ying Jiang , Shiguang Feng , Lvzhou Li

We present various results on the scheme introduced , which is a quantum spatial-search algorithm on a two-dimensional (2D) square spatial grid, realized with a 2D Dirac discrete-time quantum walk (DQW) coupled to a Coulomb electric field…

Quantum Physics · Physics 2025-02-28 Thibault Fredon , Julien Zylberman , Pablo Arnault , Fabrice Debbasch

Quantum walks are standard tools for searching graphs for marked vertices, and they often yield quadratic speedups over a classical random walk's hitting time. In some exceptional cases, however, the system only evolves by sign flips,…

Quantum Physics · Physics 2017-05-05 Thomas G. Wong , Raqueline A. M. Santos

We introduce a structured quantum search algorithm that leverages entanglement maps and a fixed-point method to minimize oracle query complexity in unsorted datasets. By partitioning qubits into rows based on their entanglement order, the…

Quantum Physics · Physics 2025-07-22 Yash Prabhat , Snigdha Thakur , Ankur Raina

We study the search kinetics of an immobile target by a concentration of randomly moving searchers. The object of the study is to optimize the probability of detection within the constraints of our model. The target is hidden on a…

Statistical Mechanics · Physics 2009-11-11 G. Oshanin , H. S. Wio , K. Lindenberg , S. F. Burlatsky

We show a simple generalization of the quantum walk algorithm for search in backtracking trees by Montanaro (ToC 2018) to the case where vertices can have different times of computation. If a vertex $v$ in the tree of depth $D$ is computed…

Quantum Physics · Physics 2025-11-25 Jevgēnijs Vihrovs

The closest pair problem is a fundamental problem of computational geometry: given a set of $n$ points in a $d$-dimensional space, find a pair with the smallest distance. A classical algorithm taught in introductory courses solves this…

Quantum Physics · Physics 2020-08-07 Scott Aaronson , Nai-Hui Chia , Han-Hsuan Lin , Chunhao Wang , Ruizhe Zhang

In this work, we consider the spatial search for a general marked state on graphs by continuous time quantum walks. As a simplest case, we compute the amplitude expression of the search for the multi-vertex uniform superposition state on…

Mathematical Physics · Physics 2018-04-10 Xi Li , Hanwu Chen , Yue Ruan , Zhihao Liu , Mengke Xu , Jianing Tan

The quantum walk dynamics obey the laws of quantum mechanics with an extra locality constraint, which demands that the evolution operator is local in the sense that the walker must visit the neighboring locations before endeavoring to…

Quantum Physics · Physics 2023-05-23 Caue F. T. Silva , Daniel Posner , Renato Portugal

We consider the quantum search problem with a continuous time quantum walk for networks of finite spectral dimension d_{s} of the network Laplacian. For general networks of fractal (integer or non-integer) dimension d_{f}, for which in…

Quantum Physics · Physics 2017-03-08 Shanshan Li , Stefan Boettcher

We propose the first \emph{local search} algorithm for Euclidean clustering that attains an $O(1)$-approximation in almost-linear time. Specifically, for Euclidean $k$-Means, our algorithm achieves an $O(c)$-approximation in $\tilde{O}(n^{1…

Data Structures and Algorithms · Computer Science 2025-04-07 Shaofeng H. -C. Jiang , Yaonan Jin , Jianing Lou , Pinyan Lu