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Related papers: Multimarked Spatial Search by Continuous-Time Quan…

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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

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

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

Spatial search is the problem of finding a marked vertex in a graph. A continuous-time quantum walk in the single-excitation subspace of an $n$ spin system solves the problem of spatial search by finding the marked vertex in $O(\sqrt{n})$…

Quantum Physics · Physics 2024-10-10 Dylan Lewis , Leonardo Banchi , Sougato Bose

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

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

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

The quantum walk is a powerful tool to develop quantum algorithms, which usually are based on searching for a vertex in a graph with multiple marked vertices, Ambainis's quantum algorithm for solving the element distinctness problem being…

Quantum Physics · Physics 2022-12-21 G. A. Bezerra , P. H. G. Lugão , R. Portugal

One of the most important algorithmic applications of quantum walks is to solve spatial search problems. A widely used quantum algorithm for this problem, introduced by Childs and Goldstone [Phys. Rev. A 70, 022314 (2004)], finds a marked…

Quantum Physics · Physics 2020-09-23 Shantanav Chakraborty , Leonardo Novo , Jérémie Roland

Spatial search on graphs is one of the most important algorithmic applications of quantum walks. To show that a quantum-walk-based search is more efficient than a random-walk-based search is a difficult problem, which has been addressed in…

Combinatorics · Mathematics 2022-02-01 Hajime Tanaka , Mohamed Sabri , Renato Portugal

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

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

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

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

Quantum walk is a potent technique for building quantum algorithms. This paper examines the quantum walk search algorithm on complete multipartite graphs with multiple marked vertices, which has not been explored before. Two specific cases…

Quantum Physics · Physics 2024-10-08 Ningxiang Chen , Meng Li , Xiaoming Sun

We contribute to fulfil the long-lasting gap in the understanding of the spatial search with multiple marked vertices. The theoretical framework is that of discrete-time quantum walks (QW), \textit{i.e.} local unitary matrices that drive…

Quantum Physics · Physics 2023-01-06 Mathieu Roget , Hachem Kadri , Giuseppe Di Molfetta

We present a novel methodological framework for quantum spatial search, generalising the Childs & Goldstone ($\mathcal{CG}$) algorithm via alternating applications of marked-vertex phase shifts and continuous-time quantum walks. We…

Quantum Physics · Physics 2021-09-30 S. Marsh , J. B. Wang

We study the discrete-time quantum walk-based search for a marked vertex on a graph. By considering various structures in which not all vertices are equivalent, we investigate the relationship between the successful search probability and…

Quantum Physics · Physics 2015-03-17 Scott D. Berry , Jingbo B. Wang

We study scattering quantum walks on highly symmetric graphs and use the walks to solve search problems on these graphs. The particle making the walk resides on the edges of the graph, and at each time step scatters at the vertices. All of…

Quantum Physics · Physics 2009-01-27 Daniel Reitzner , Mark Hillery , Edgar Feldman , Vladimir Buzek

In quantum computing, the quantum walk search algorithm is designed for locating fixed marked nodes within a graph. However, when multiple marked nodes exist, the conventional search algorithm lacks the capacity to simultaneously amplify…

Quantum Physics · Physics 2024-02-06 Himanshu Sahu , Kallol Sen
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