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Related papers: Spatial Search on Grids with Minimum Memory

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The spatial search problem aims to find a marked vertex of a finite graph using a dynamic with two constraints: (1) The walker has no compass and (2) the walker can check whether a vertex is marked only after reaching it. This problem is a…

Quantum Physics · Physics 2022-06-02 Hajime Tanaka , Mohamed Sabri , Renato Portugal

We address quantum spatial search on graphs and its implementation by continuous-time quantum walks in the presence of dynamical noise. In particular, we focus on search on the complete graph and on the star graph of order $N$, proving that…

Quantum Physics · Physics 2018-11-29 Marco Cattaneo , Matteo A. C. Rossi , Matteo G. A. Paris , Sabrina Maniscalco

Continuous-time quantum walks provide a natural framework to tackle the fundamental problem of finding a node among a set of marked nodes in a graph, known as spatial search. Whether spatial search by continuous-time quantum walk provides a…

Quantum Physics · Physics 2022-10-24 Simon Apers , Shantanav Chakraborty , Leonardo Novo , Jérémie Roland

In the typical spatial search problems solved by continuous-time quantum walk, changing the location of the marked vertices does not alter the search problem. In this paper, we consider search when this is no longer true. In particular, we…

Quantum Physics · Physics 2016-04-11 Thomas G. Wong

The problem of finding a marked node in a graph can be solved by the spatial search algorithm based on continuous-time quantum walks (CTQW). However, this algorithm is known to run in optimal time only for a handful of graphs. In this work,…

Quantum Physics · Physics 2016-03-23 Shantanav Chakraborty , Leonardo Novo , Andris Ambainis , Yasser Omar

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

Shenvi, Kempe and Whaley's quantum random-walk search (SKW) algorithm [Phys. Rev. A 67, 052307 (2003)] is known to require $O(\sqrt N)$ number of oracle queries to find the marked element, where $N$ is the size of the search space. The…

Quantum Physics · Physics 2009-03-20 V. Potocek , A. Gabris , T. Kiss , I. Jex

The spatial search problem consists in minimizing the number of steps required to find a given site in a network, under the restriction that only oracle queries or translations to neighboring sites are allowed. In this paper, a quantum…

Quantum Physics · Physics 2012-05-18 G. Abal , R. Donangelo , F. L. Marquezino , R. Portugal

An ideal quantum walk transitions from one vertex to another with perfect fidelity, but in physical systems, the particle may be hindered by potential energy barriers. Then the particle has some amplitude of tunneling through the barriers,…

Quantum Physics · Physics 2016-11-10 Thomas G. Wong

This work examines the time complexity of quantum search algorithms on combinatorial $t$-designs with multiple marked elements using the continuous-time quantum walk. Through a detailed exploration of $t$-designs and their incidence…

Quantum Physics · Physics 2025-04-08 Pedro H. G. Lugão , Renato Portugal

A discrete time quantum walk is known to be the single-particle sector of a quantum cellular automaton. Searching in this mathematical framework has interested the community since a long time. However, most results consider spatial search…

Quantum Physics · Physics 2023-12-27 Mathieu Roget , Giuseppe Di Molfetta

The Scattering Quantum Random Walk scheme has found success as a basis for search algorithms on highly symmetric graph structures. In this paper we examine its effectiveness at locating a specially marked vertex on square grid graphs,…

Quantum Physics · Physics 2019-01-23 Daniel Koch

Quantum walks have been useful for designing quantum algorithms that outperform their classical versions for a variety of search problems. Most of the papers, however, consider a search space containing a single marked element only. We show…

Quantum Physics · Physics 2017-10-12 Nikolajs Nahimovs , Raqueline A. M. Santos

We consider the problem of searching a general $d$-dimensional lattice of $N$ vertices for a single marked item using a continuous-time quantum walk. We demand locality, but allow the walk to vary periodically on a small scale. By…

Quantum Physics · Physics 2014-09-08 Andrew M. Childs , Yimin Ge

In this paper we present a novel quantum algorithm, namely the quantum grid search algorithm, to solve a special search problem. Suppose $ k $ non-empty buckets are given, such that each bucket contains some marked and some unmarked items.…

Quantum Physics · Physics 2019-09-11 Alok Shukla , Prakash Vedula

We analyse the eigenvalue and eigenvector structure of the flip-flop quantum walk on regular graphs, explicitly demonstrating how it is quadratically faster than the classical random walk. Then we use it in a controlled spatial search…

Quantum Physics · Physics 2018-12-18 Abhijith J. , Apoorva Patel

To investigate the performance of quantum information tasks on networks whose topology changes in time, we study the spatial search algorithm by continuous time quantum walk to find a marked node on a random temporal network. We consider a…

Quantum Physics · Physics 2017-11-30 Shantanav Chakraborty , Leonardo Novo , Serena Di Giorgio , Yasser Omar

Quantum computing promises to improve the information processing power to levels unreachable by classical computation. Quantum walks are heading the development of quantum algorithms for searching information on graphs more efficiently than…

We provide numerical evidence that the nonlinear searching algorithm introduced by Wong and Meyer \cite{meyer2013nonlinear}, rephrased in terms of quantum walks with effective nonlinear phase, can be extended to the finite 2-dimensional…

Quantum Physics · Physics 2020-11-16 Basile Herzog , Giuseppe Di Molfetta

In this paper, we show reduction methods for search algorithms on graphs using quantum walks. By using a graph partitioning method called equitable partition for the the given graph, we determine "effective subspace" for the search…

Quantum Physics · Physics 2018-12-18 Yusuke Ide