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In this paper, we consider a continuous-time quantum walk based search algorithm. We introduce equitable partition of the graph and perfect state transfer on it. By these two methods, we can calculate the success probability and the finding…

Quantum Physics · Physics 2022-09-19 Yusuke Ide , Akihiro Narimatsu

Quantum search has emerged as one of the most promising fields in quantum computing. State-of-the-art quantum search algorithms enable the search for specific elements in a distribution by monotonically increasing the density of these…

Optimization and Control · Mathematics 2025-01-14 Rodolphe Griset , Ioannis Lavdas , Jiri Guth Jarkovsky

We design a space-efficient algorithm for performing depth-first search traversal(DFS) of a graph in $O(m+n\log^* n)$ time using $O(n)$ bits of space. While a normal DFS algorithm results in a DFS-tree (in case the graph is connected), our…

Data Structures and Algorithms · Computer Science 2018-10-18 Jayesh Choudhari , Manoj Gupta , Shivdutt Sharma

Suppose we have n algorithms, quantum or classical, each computing some bit-value with bounded error probability. We describe a quantum algorithm that uses O(sqrt{n}) repetitions of the base algorithms and with high probability finds the…

Quantum Physics · Physics 2017-01-03 Peter Hoyer , Michele Mosca , Ronald de Wolf

Adding self-loops at each vertex of a graph improves the performance of quantum walks algorithms over loopless algorithms. Many works approach quantum walks to search for a single marked vertex. In this article, we experimentally address…

Quantum Physics · Physics 2021-12-16 Luciano S. de Souza , Jonathan H. A. de Carvalho , Tiago A. E. Ferreira

In this paper, we present a novel formulation of traditional sampling-based motion planners as database-oracle structures that can be solved via quantum search algorithms. We consider two complementary scenarios: for simpler sparse…

Quantum Physics · Physics 2023-10-25 Paul Lathrop , Beth Boardman , Sonia Martínez

A quantum walk algorithm can detect the presence of a marked vertex on a graph quadratically faster than the corresponding random walk algorithm (Szegedy, FOCS 2004). However, quantum algorithms that actually find a marked element…

Quantum Physics · Physics 2019-03-19 Andris Ambainis , András Gilyén , Stacey Jeffery , Martins Kokainis

We investigate a set of discrete-time quantum search algorithms on the n-dimensional hypercube following a proposal by Shenvi, Kempe and Whaley. We show that there exists a whole class of quantum search algorithms in the symmetry reduced…

Quantum Physics · Physics 2010-05-24 Birgit Hein , Gregor Tanner

Given an item and a list of values of size $N$. It is required to decide if such item exists in the list. Classical computer can search for the item in O(N). The best known quantum algorithm can do the job in $O(\sqrt{N})$. In this paper, a…

Quantum Physics · Physics 2008-11-27 Ahmed Younes

A quantum algorithm is known that solves an unstructured search problem in a number of iterations of order $\sqrt{d}$, where $d$ is the dimension of the search space, whereas any classical algorithm necessarily scales as $O(d)$. It is shown…

Quantum Physics · Physics 2009-10-31 N. J. Cerf , L. K. Grover , C. P. Williams

In this paper, we analyze the potential for new types of searches using the formalism of scattering random walks on Quantum Computers. Given a particular type of graph consisting of nodes and connections, a "Tree Maze", we would like to…

Quantum Physics · Physics 2018-01-17 Daniel Koch , Mark Hillery

In typical discrete-time quantum walk algorithms, one measures the position of the walker while ignoring its internal spin/coin state. Rather than neglecting the information in this internal state, we show that additionally measuring it…

Quantum Physics · Physics 2016-10-20 Krišjānis Prūsis , Jevgēnijs Vihrovs , Thomas G. Wong

In this tutorial, which contains some original results, we bridge the fields of quantum computing algorithms, conservation laws, and many-body quantum systems by examining three algorithms for searching an unordered database of size $N$…

Quantum Physics · Physics 2025-08-29 David A. Meyer , Thomas G. Wong

We numerically study the quantum walk search algorithm of Shenvi, Kempe and Whaley [PRA \textbf{67} 052307] and the factors which affect its efficiency in finding an individual state from an unsorted set. Previous work has focused purely on…

Quantum Physics · Physics 2019-02-20 Neil B. Lovett , Matthew Everitt , Robert M. Heath , Viv Kendon

Quantum walks are powerful kernels in quantum computing protocols that possess strong capabilities in speeding up various simulation and optimisation tasks. One striking example is given by quantum walkers evolving on glued trees for their…

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

Can Grover's algorithm speed up search of a physical region - for example a 2-D grid of size sqrt(n) by sqrt(n)? The problem is that sqrt(n) time seems to be needed for each query, just to move amplitude across the grid. Here we show that…

Quantum Physics · Physics 2007-05-23 Scott Aaronson , Andris Ambainis

This paper proposes a computational procedure that applies a quantum algorithm to train classical artificial neural networks. The goal of the procedure is to apply quantum walk as a search algorithm in a complete graph to find all synaptic…

Quantum Physics · Physics 2021-09-06 Luciano S. de Souza , Jonathan H. A. de Carvalho , Tiago A. E. Ferreira

This work describes a new algorithm for creating a superposition over the edge set of a graph, encoding a quantum sample of the random walk stationary distribution. The algorithm requires a number of quantum walk steps scaling as…

Quantum Physics · Physics 2019-04-26 Simon Apers

There exist two types of configurations of marked vertices on a two-dimensional grid, known as the {\it exceptional configurations}, which are hard to find by the discrete-time quantum walk algorithms. In this article, we provide a…

Quantum Physics · Physics 2025-07-04 Pulak Ranjan Giri