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Discrete-time quantum walks are considered a counterpart of random walks and the study for them has been getting attention since around 2000. In this paper, we focus on a quantum walk which generates a probability distribution splitting to…

Quantum Physics · Physics 2018-05-08 Takuya Machida

The coherent superposition of position states in a quantum walk (QW) can be precisely engineered towards the desired distributions to meet the need of quantum information applications. The coherent distribution can make full use of quantum…

Very much as its classical counterpart, quantum cellular automata are expected to be a great tool for simulating complex quantum systems. Here we introduce a partitioned model of quantum cellular automata and show how it can simulate, with…

Quantum Physics · Physics 2018-03-07 Pedro C. S. Costa , Renato Portugal , Fernando de Melo

Focusing on a continuous-time quantum walk on $\mathbb{Z}=\left\{0,\pm 1,\pm 2,\ldots\right\}$, we analyze a probability distribution with which the quantum walker is observed at a position. The walker launches off at a localized state and…

Quantum Physics · Physics 2023-09-06 Takuya Machida

We study quantum transport on finite discrete structures and we model the process by means of continuous-time quantum walks. A direct and effective comparison between quantum and classical walks can be attained based on the average…

Quantum Physics · Physics 2008-10-08 E. Agliari , A. Blumen , O. Muelken

Quantum walks are considered to be quantum counterparts of random walks.They show us impressive probability distributions which are different from those of random walks.That fact has been precisely proved in terms of mathematics and some of…

Quantum Physics · Physics 2016-07-13 Takuya Machida

The development of quantum walks in the context of quantum computation, as generalisations of random walk techniques, led rapidly to several new quantum algorithms. These all follow unitary quantum evolution, apart from the final…

Quantum Physics · Physics 2008-03-02 Viv Kendon

The quantum walks in the lattice spaces are represented as unitary evolutions. We find a generator for the evolution and apply it to further understand the walks. We first extend the discrete time quantum walks to continuous time walks.…

Mathematical Physics · Physics 2013-05-09 Chul Ki Ko , Hyun Jae Yoo

Quantum walk is a key operation in quantum computing, simulation, communication and information. Here, we report for the first time the demonstration of quantum walks and localized quantum walks in a new type of optical fibers having a ring…

Quantum versions of random walks on the line and the cycle show a quadratic improvement over classical random walks in their spreading rates and mixing times respectively. Non-unitary quantum walks can provide a useful optimisation of these…

Quantum Physics · Physics 2008-03-25 Viv Kendon , Olivier Maloyer

Quantum walks on graphs are ubiquitous in quantum computing finding a myriad of applications. Likewise, random walks on graphs are a fundamental building block for a large number of algorithms with diverse applications. While the…

Quantum Physics · Physics 2020-12-09 Matheus G. Andrade , Franklin Marquezino , Daniel R. Figueiredo

We address the performance of a coin-biased quantum walk as a generator for non-classical position states of the walker. We exploit a phenomenon of coherent localisation in the position space --- resulting from the choice of small values of…

Quantum Physics · Physics 2018-01-09 H. Majury , J. Boutari , E. O'Sullivan , A. Ferraro , M. Paternostro

A connection between the asymptotic behavior of the open quantum walk and the spectrum of a generalized quantum coins is studied. For the case of simultaneously diagonalizable transition operators an exact expression for probability…

Quantum Physics · Physics 2014-02-07 I. Sinayskiy , F. Petruccione

Multilayer network is a potent platform which paves a way to study the interactions among entities in various networks with multiple types of relationships. In this study, the dynamics of discrete-time quantum walk on a multilayer network…

Quantum Physics · Physics 2023-10-05 M. N. Jayakody , Priodyuti Pradhan , Dana Ben Porath , E. Cohen

Manifestations of quantum coherence in the electronic conductance through nearly closed quantum dots in the Coulomb blockade regime are addressed. We show that quantum coherent tunneling processes explain some puzzling statistical features…

Mesoscale and Nanoscale Physics · Physics 2015-05-26 L. E. F. Foa Torres , C. H. Lewenkopf , H. M. Pastawski

Quantum walks are promising tools based on classical random walks, with plenty of applications such as many variants of optimization. Here we introduce the semiclassical walks in discrete time, which are algorithms that combines classical…

Quantum Physics · Physics 2023-07-25 Sergio A. Ortega , Miguel A. Martin-Delgado

We introduce the quantum quincunx, which physically demonstrates the quantum walk and is analogous to Galton's quincunx for demonstrating the random walk. In contradistinction to the theoretical studies of quantum walks over orthogonal…

Quantum Physics · Physics 2016-09-08 Barry C. Sanders , Stephen D. Bartlett , Ben Tregenna , Peter L. Knight

We analyze the quantum walk on a cycle using discrete Wigner functions as a way to represent the states and the evolution of the walker. The method provides some insight on the nature of the interference effects that make quantum and…

Quantum Physics · Physics 2009-11-10 C. C. Lopez , J. P. Paz

We report on the possibility of controlling quantum random walks with a step-dependent coin. The coin is characterized by a (single) rotation angle. Considering different rotation angles, one can find diverse probability distributions for…

Quantum Physics · Physics 2018-08-23 S. Panahiyan , S. Fritzsche

The quantum walk is a dynamical protocol which describes the motion of spinful particles on a lattice. Also, it has been demonstrated to be a powerful platform to explore topological quantum matter. Recently, the quantum walk in coherent…

Quantum Physics · Physics 2018-09-19 Zi-Yong Ge , Heng Fan