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Related papers: Quantum walk based search algorithms

200 papers

The staggered quantum walk model allows to establish an unprecedented connection between discrete-time quantum walks and graph theory. We call attention to the fact that a large subclass of the coined model is included in Szegedy's model,…

Quantum Physics · Physics 2016-07-06 Renato Portugal

We present a continuous time quantum search algorithm analogous to Grover's. In particular, the optimal search time for this algorithm is proportional to $\sqrt{N}$, where $N$ is the database size. This search algorithm can be implemented…

Quantum Physics · Physics 2009-11-11 A. Romanelli , A. Auyuanet , R. Donangelo

We present a quantum algorithm for ranking the nodes on a network in their order of importance. The algorithm is based on a directed discrete-time quantum walk, and works on all directed networks. This algorithm can theoretically be applied…

Quantum Physics · Physics 2020-04-02 Prateek Chawla , Roopesh Mangal , C. M. Chandrashekar

For a continuous-time quantum walk on a line the variance of the position observable grows quadratically in time, whereas, for its classical counterpart on the same graph, it exhibits a linear, diffusive, behaviour. A quantum walk, thus,…

Quantum Physics · Physics 2008-01-30 Diego de Falco , Dario Tamascelli

The lazy random walk, where the walker has some probability of staying put, is a useful tool in classical algorithms. We propose a quantum analogue, the lackadaisical quantum walk, where each vertex is given $l$ self-loops, and we…

Quantum Physics · Physics 2017-09-26 Thomas G. Wong

Closed quantum systems follow a unitary time evolution that can be simulated on quantum computers. By incorporating non-unitary effects via, e.g., measurements on ancilla qubits, these algorithms can be extended to open-system dynamics,…

Quantum Physics · Physics 2025-05-07 Peter J. Eder , Jernej Rudi Finžgar , Sarah Braun , Christian B. Mendl

We identify a key difference between quantum search by discrete- and continuous-time quantum walks: a discrete-time walk typically performs one walk step per oracle query, whereas a continuous-time walk can effectively perform multiple walk…

Quantum Physics · Physics 2015-08-24 Thomas G. Wong , Andris Ambainis

In this paper we show how to generalize the quantum approximate counting technique developed by Brassard, H{\o}yer and Tapp [ICALP 1998] to a more general setting: estimating the number of marked states of a Markov chain (a Markov chain can…

Quantum Physics · Physics 2023-12-29 François Le Gall , Iu-Iong Ng

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

Quantum random walks use interference to obtain faster state space exploration, which can be used for algorithmic purposes. Photonic technologies provide a natural platform for many recent experimental demonstrations. Here we analyze…

Quantum Physics · Physics 2022-03-04 Ricardo M. R. Adão , Manuel Caño-García , Jana B. Nieder , Ernesto F. Galvão

A random walk is known as a random process which describes a path including a succession of random steps in the mathematical space. It has increasingly been popular in various disciplines such as mathematics and computer science.…

Social and Information Networks · Computer Science 2020-08-11 Feng Xia , Jiaying Liu , Hansong Nie , Yonghao Fu , Liangtian Wan , Xiangjie Kong

Random walks simulate the randomness of objects, and are key instruments in various fields such as computer science, biology and physics. The counter part of classical random walks in quantum mechanics are the quantum walks. Quantum walk…

Social and Information Networks · Computer Science 2023-01-09 Annamaria Ficara , Giacomo Fiumara , Pasquale De Meo , Salvatore Catanese

The quantum-walk-based spatial search problem aims to find a marked vertex using a quantum walk on a graph with marked vertices. We describe a framework for determining the computational complexity of spatial search by continuous-time…

Quantum Physics · Physics 2024-12-25 Pedro H. G. Lugão , Renato Portugal , Mohamed Sabri , Hajime Tanaka

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

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 this paper we construct (nonhomogeneous) quantum Markov chains associated with open quantum random walks. The quantum Markov chain, like the classical Markov chain, is a fundamental tool for the investigation of the basic properties such…

Mathematical Physics · Physics 2019-10-02 Ameur Dhahri , Chul Ki Ko , Hyun Jae Yoo

Quantum walks have emerged as a transformative paradigm in quantum information processing and can be applied to various graph problems. This study explores discrete-time quantum walks on simplicial complexes, a higher-order generalization…

Quantum Physics · Physics 2024-05-24 Euijun Song

In this paper, we propose a circuit design for implementing quantum walks on complex networks. Quantum walks are powerful tools for various graph-based applications such as spatial search, community detection, and node classification.…

Quantum Physics · Physics 2026-04-24 Rei Sato , Kazuhiro Saito

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

Coined Quantum Walks (QWs) are being used in many contexts with the goal of understanding quantum systems and building quantum algorithms for quantum computers. Alternative models such as Szegedy's and continuous-time QWs were proposed…

Quantum Physics · Physics 2017-01-31 Renato Portugal