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We use simple deterministic dynamical systems as coins in studying quantum walks. These dynamical systems can be chosen to display, in the classical limit, a range of behaviors from the integrable to chaotic, or deterministically random. As…

Quantum Physics · Physics 2007-05-23 Arul Lakshminarayan

In discrete-time quantum walk (DTQW) the walker's coin space entangles with the position space after the very first step of the evolution. This phenomenon may be exploited to obtain the value of the coin parameter $\theta$ by performing…

Quantum Physics · Physics 2019-07-10 Shivani Singh , C. M. Chandrashekar , Matteo G. A. Paris

We treat a quantum walk (QW) on the line whose quantum coin at each vertex tends to be the identity as the distance goes to infinity. We obtain a limit theorem that this QW exhibits localization with not an exponential but a "power-law"…

Mathematical Physics · Physics 2014-05-08 Norio Konno , Etsuo Segawa

A Plastic Quantum Walk admits both continuous time and continuous spacetime. The model has been recently proposed by one of the authors in \cite{molfetta2019quantum}, leading to a general quantum simulation scheme for simulating fermions in…

Quantum Physics · Physics 2020-11-25 Michael Manighalam , Giuseppe Di Molfetta

We formulate a framework for discrete-time quantum walks, motivated by classical random walks with memory. We present a specific representation of the classical walk with memory 2 on which this is based. The framework has no need for coin…

We consider an special dynamics of a quantum walk (QW) on a line. Initially, the walker localized at the origin of the line with arbitrary chirality, evolves to an asymptotic stationary state. In this stationary state a measurement is…

Quantum Physics · Physics 2016-10-05 Alejandro Romanelli

The behaviour of random quantum walks is known to be diffusive. Here we study discrete time quantum walks in weak stochastic gauge fields. In the case of position and spin dependent gauge field, we observe a transition from ballistic to…

Quantum Physics · Physics 2024-06-21 Jan Wójcik

We study one-dimensional quantum walk with four internal degrees of freedom resulted from two entangled qubits. We will demonstrate that the entanglement between the qubits and its corresponding coin operator enable one to steer the…

Quantum Physics · Physics 2020-07-01 S. Panahiyan , S. Fritzsche

Discrete time quantum walks are known to be universal for quantum computation. This has been proven by showing that they can simulate a universal quantum gate set. In this paper, we examine computation by quantum walks in terms of language…

Formal Languages and Automata Theory · Computer Science 2014-08-04 Katie Barr , Viv Kendon

Recently, quantized versions of random walks have been explored as effective elements for quantum algorithms. In the simplest case of one dimension, the theory has remained divided into the discrete-time quantum walk and the continuous-time…

Quantum Physics · Physics 2009-11-13 Frederick W. Strauch

We have recently proposed a two-dimensional quantum walk where the requirement of a higher dimensionality of the coin space is substituted with the alternance of the directions in which the walker can move [C. Di Franco, M. Mc Gettrick, and…

Quantum Physics · Physics 2011-10-27 C. Di Franco , M. Mc Gettrick , T. Machida , Th. Busch

The extremely fascinating behaviors of the quantum walks of particles, which differ much from the classical counterparts, have attracted many physicists. Here we investigate another interesting part of the quantum walks, that is the quantum…

Quantum Physics · Physics 2010-11-23 Tian-Li Feng , Yong-Sheng Zhang , Guang-Ming Zhao , Sheng Liu , Guang-Can Guo

In this work, we study the effect of a moving detector on a discrete time one dimensional Quantum Random Walk where the movement is realized in the form of hopping/shifts. The occupation probability $f(x,t;n,s)$ is estimated as the number…

Quantum Physics · Physics 2023-07-10 Md Aquib Molla , Sanchari Goswami

The discrete-time quantum walk (QW) has been extensively and intensively investigated for the last decade, whose coin operator is defined by a unitary matrix. We extend the QW to a walk determined by a unitary matrix whose component is…

Quantum Physics · Physics 2015-05-05 Norio Konno

We investigated discrete-time quantum walks with an arbitary unitary coin. Here we discover that the average position $<x> =\max(<x> \sin(\alpha+\gamma)$, while the initial state is $1/\sqrt{2}(\mid0L>+i\mid0R>)$. We prove the result and…

Quantum Physics · Physics 2015-06-11 Min Li , YOng-Sheng Zhang , Guang-Can Guo

We propose an experimental realization of discrete quantum random walks using neutral atoms trapped in optical lattices. The random walk is taking place in position space and experimental implementation with present day technology --even…

Quantum Physics · Physics 2016-08-16 W. Dür , R. Raussendorf , V. M. Kendon , H. -J. Briegel

Open Quantum Walks (OQWs) are exclusively driven by dissipation and are formulated as completely positive trace preserving (CPTP) maps on underlying graphs. The microscopic derivation of discrete and continuous in time OQWs is presented. It…

Quantum Physics · Physics 2015-10-07 Ilya Sinayskiy , Francesco Petruccione

One-parameter family of discrete-time quantum-walk models on the square lattice, which includes the Grover-walk model as a special case, is analytically studied. Convergence in the long-time limit $t \to \infty$ of all joint moments of two…

Quantum Physics · Physics 2008-06-20 Kyohei Watabe , Naoki Kobayashi , Makoto Katori , Norio Konno

We propose a variation of the quantum walk on a circle in phase space by conjoining the Hadamard coin flip with simultaneous displacement of the walker's location in phase space and show that this generalization is a proper quantum walk…

Quantum Physics · Physics 2008-05-26 Peng Xue , Barry C. Sanders

We consider a discrete-time 2-state quantum walk on the line. The state of the quantum walker evolves according to a rule which is determined by a coin-flip operator and a position-shift operator. In this paper we take a 3-periodic time…

Quantum Physics · Physics 2015-06-03 F. Alberto Grünbaum , Takuya Machida