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In this paper, we study discrete-time quantum walks on one-dimensional lattices. We find that the coherent dynamics depends on the initial states and coin parameters. For infinite size of lattice, we derive an explicit expression for the…

Cellular Automata and Lattice Gases · Physics 2015-05-18 Xin-Ping Xu

Theoretical and applied studies of quantum walks are abundant in quantum science and technology thanks to their relative simplicity and versatility. Here we derive closed-form expressions for the probability distribution of quantum walks on…

Quantum Physics · Physics 2023-08-11 Mahesh N. Jayakody , Eliahu Cohen

Properties of the probability distribution generated by a discrete-time quantum walk, such as the number of peaks it contains, depend strongly on the choice of the initial condition. In the present paper we discuss from this point of view…

Quantum Physics · Physics 2017-01-03 Martin Stefanak , Iva Bezdekova , Igor Jex

We study the asymptotic position distribution of general quantum walks on a lattice, including walks with a random coin, which is chosen from step to step by a general Markov chain. In the unitary (i.e., non-random) case, we allow any…

Quantum Physics · Physics 2011-04-21 Andre Ahlbrecht , Holger Vogts , Albert H. Werner , Reinhard F. Werner

A quantum walk places a traverser into a superposition of both graph location and traversal "spin." The walk is defined by an initial condition, an evolution determined by a unitary coin/shift-operator, and a measurement based on the…

Quantum Physics · Physics 2015-11-25 Marko A. Rodriguez , Jennifer H. Watkins

We investigate the relation between transport properties and entanglement between the internal (spin) and external (position) degrees of freedom in one-dimensional discrete time quantum walks. We obtain closed-form expressions for the…

Quantum Physics · Physics 2020-04-08 Alexandre C. Orthey , Edgard P. M. Amorim

In the literature, there are numerous studies of one-dimensional discrete-time quantum walks (DTQWs) using a moving shift operator. However, there is no exact solution for the limiting probability distributions of DTQWs on cycles using a…

Quantum Physics · Physics 2016-10-20 Xin-Ping Xu , Yusuke Ide

The quantum walk (QW) is the term given to a family of algorithms governing the evolution of a discrete quantum system and as such has a founding role in the study of quantum computation. We contribute to the investigation of QW phenomena…

Quantum Physics · Physics 2015-07-02 Hao Luo , Peng Xue

We show that a quantum state transfer, previously studied as a continuous time process in networks of interacting spins, can be achieved within the model of discrete time quantum walks with position dependent coin. We argue that due to…

Quantum Physics · Physics 2016-10-05 Pawel Kurzynski , Antoni Wojcik

Quantum walks and random walks bear similarities and divergences. One of the most remarkable disparities affects the probability of finding the particle at a given location: typically, almost a flat function in the first case and a…

Quantum Physics · Physics 2017-06-21 Miquel Montero

This work focuses on the study of quantum stochastic walks, which are a generalization of coherent, i. e. unitary quantum walks. Our main goal is to present a measure of a coherence of the walk. To this end, we utilize the asymptotic…

Quantum Physics · Physics 2018-03-21 Krzysztof Domino , Adam Glos , Mateusz Ostaszewski , Łukasz Pawela , Przemysław Sadowski

The dynamics of a one dimensional quantum walker on the lattice with two internal degrees of freedom, the coin states, is considered. The discrete time unitary dynamics is determined by the repeated action of a coin operator in U(2) on the…

Mathematical Physics · Physics 2010-04-26 Alain Joye , Marco Merkli

We show that probability is locally conserved in discrete time quantum walks, corresponding to a particle evolving in discrete space and time. In particular, for a spatial structure represented by an arbitrary directed graph, and any…

Quantum Physics · Physics 2021-05-05 Samuel T. Mister , Benjamin J. Arayathel , Anthony J. Short

We introduce an analytically treatable spin decoherence model for quantum walk on a line that yields the exact position probability distribution of an unbiased classical random walk at all-time scales. This spin decoherence model depicts a…

Quantum Physics · Physics 2018-09-05 Mahesh N. Jayakody , Asiri Nanayakkara

Properties of one dimensional discrete-time quantum walks are sensitive to the presence of inhomogeneities in the substrate, which can be generated by defining position dependent coin operators. Deterministic aperiodic sequences of two or…

Quantum Physics · Physics 2018-11-08 R. F. S. Andrade , A. M. C. Souza

We propose an implementation of a quantum walk on a circle on an optomechanical system by encoding the walker on the phase space of a radiation field and the coin on a two-level state of a mechanical resonator. The dynamics of the system is…

Quantum Physics · Physics 2015-09-24 Jalil Khatibi Moqadam , Renato Portugal , Marcos Cesar de Oliveira

In discrete time, coined quantum walks, the coin degrees of freedom offer the potential for a wider range of controls over the evolution of the walk than are available in the continuous time quantum walk. This paper explores some of the…

Quantum Physics · Physics 2009-11-10 Ben Tregenna , Will Flanagan , Rik Maile , Viv Kendon

We perform the scattering analysis of the evolution operator of quantum walks with an anisotropic coin, and we prove a weak limit theorem for their asymptotic velocity. The quantum walks that we consider include one-defect models, two-phase…

Mathematical Physics · Physics 2018-06-13 S. Richard , A. Suzuki , R. Tiedra de Aldecoa

We investigate the evolution of a discrete-time one-dimensional quantum walk driven by a position-dependent coin. The rotation angle which depends upon the position of a quantum particle parameterizes the coin operator. For different values…

Quantum Physics · Physics 2020-08-26 Rashid Ahmad , Uzma Sajjad , Muhammad Sajid

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a…

Quantum Physics · Physics 2012-10-01 Salvador E. Venegas-Andraca