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Quantum walks, being the quantum analogue of classical random walks, are expected to provide a fruitful source of quantum algorithms. A few such algorithms have already been developed, including the `glued trees' algorithm, which provides…

Quantum Physics · Physics 2009-10-29 B. L. Douglas , J. B. Wang

The Maximum Matching problem has a quantum query complexity lower bound of $\Omega(n^{3/2})$ for graphs on $n$ vertices represented by an adjacency matrix. The current best quantum algorithm has the query complexity $O(n^{7/4})$, which is…

Quantum Physics · Physics 2025-10-31 Alcides Gomes Andrade Júnior , Akira Matsubayashi

We investigate the generalisation of quantum search of unstructured and totally ordered sets to search of partially ordered sets (posets). Two models for poset search are considered. In both models, we show that quantum algorithms can…

Quantum Physics · Physics 2009-06-18 Ashley Montanaro

Quantum walk followed by some amplitude amplification technique has been successfully used to search for marked vertices on various graphs. Lackadaisical quantum walk can search for target vertices on graphs without the help of any…

Quantum Physics · Physics 2025-03-07 Pulak Ranjan Giri

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

This paper examines the performance of spatial search where the Grover diffusion operator is replaced by continuous-time quantum walks on a class of interdependent networks. We prove that for a set of optimal quantum walk times and marked…

Quantum Physics · Physics 2021-08-26 S. Marsh , J. B. Wang

We show how a quantum walk can be used to find a marked edge or a marked complete subgraph of a complete graph. We employ a version of a quantum walk, the scattering walk, which lends itself to experimental implementation. The edges are…

Quantum Physics · Physics 2015-05-14 Mark Hillery , Daniel Reitzner , Vladimir Buzek

Grover's quantum search algorithm provides a way to speed up combinatorial search, but is not directly applicable to searching a physical database. Nevertheless, Aaronson and Ambainis showed that a database of N items laid out in d spatial…

Quantum Physics · Physics 2007-05-23 Andrew M. Childs , Jeffrey Goldstone

$ $In its usual form, Grover's quantum search algorithm uses $O(\sqrt{N})$ queries and $O(\sqrt{N} \log N)$ other elementary gates to find a solution in an $N$-bit database. Grover in 2002 showed how to reduce the number of other gates to…

Quantum Physics · Physics 2016-10-24 Srinivasan Arunachalam , Ronald de Wolf

We give a quantum algorithm for finding a marked element on the grid when there are multiple marked elements. Our algorithm uses quadratically fewer steps than a random walk on the grid, ignoring logarithmic factors. This is the first known…

Quantum Physics · Physics 2017-07-04 Peter Hoyer , Mojtaba Komeili

Quantum Search Algorithm made a big impact by being able to solve the search problem for a set with $N$ elements using only $O(\sqrt{N})$ steps. Unfortunately, it is impossible to reduce the order of the complexity of this problem, however,…

Quantum Physics · Physics 2022-07-25 Umut Çalıkyılmaz , Sadi Turgut

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 running time of a quantum walk search algorithm depends on both the structure of the search space (graph) and the configuration of marked locations. While the first dependence have been studied in a number of papers, the second…

Quantum Physics · Physics 2015-07-15 Nikolajs Nahimovs , Alexander Rivosh

This paper deals with the problem of the requirements for quantum systems that enable one to design efficient quantum algorithms. We rise the issue of the possibility to utilise the non-complete networks for algorithmic purposes. In…

Quantum Physics · Physics 2015-06-15 Przemysław Sadowski

Quantum search is a quantum mechanical technique for searching N possibilities in only sqrt(N) steps. This has been proved to be the best possible algorithm for the exhuastive search problem in the sense the number of queries it requires…

Quantum Physics · Physics 2009-11-07 Lov K. Grover

The coined quantum walk is a discretization of the Dirac equation of relativistic quantum mechanics, and it is the basis of many quantum algorithms. We investigate how it searches the complete bipartite graph of $N$ vertices for one of $k$…

Quantum Physics · Physics 2019-03-04 Mason L. Rhodes , Thomas G. Wong

In this paper, we propose an extension of quantum searches on graphs driven by quantum walks to simplicial complexes. To this end, we newly define a quantum walk on simplicial complex which is an alternative of preceding studies by authors.…

Mathematical Physics · Physics 2017-12-06 Kaname Matsue , Osamu Ogurisu , Etsuo Segawa

Continuous-time quantum walks are natural tools for spatial search, where one searches for a marked vertex in a graph. Sometimes, the structure of the graph causes the walker to get trapped, such that the probability of finding the marked…

Quantum Physics · Physics 2016-08-10 Thomas G. Wong , Pascal Philipp

Given an undirected, weighted graph, with $n$ vertices and $m$ edges, and two special vertices $s$ and $t$, the problem is to find the shortest path between them. We give two bounded-error quantum algorithms with improved runtime in the…

Quantum Physics · Physics 2026-03-20 Adam Wesołowski , Stephen Piddock

We show that it is possible to use a quantum walk to find a path from one marked vertex to another. In the specific case of $M$ stars connected in a chain, one can find the path from the first star to the last one in $O(M\sqrt{N})$ steps,…

Quantum Physics · Physics 2017-09-19 Daniel Reitzner , Mark Hillery , Daniel Koch