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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

Hitting the exit node from the entrance node faster on a graph is one of the properties that quantum walk algorithms can take advantage of to outperform classical random walk algorithms. Especially, continuous-time quantum walks on…

It is demonstrated that in contrast to the well-known case with a quantum particle moving freely in a real line, the wave packets corresponding to the coherent states for a free quantum particle on a circle do not spread but develop…

Quantum Physics · Physics 2009-11-06 K. Kowalski , J. Rembielinski

We study the quantum walk subjected to measurements with a L\'evy waiting-time distribution. We find that the system has a sub-ballistic behavior instead of a diffusive one. We obtain an analytical expression for the exponent of the power…

Quantum Physics · Physics 2009-11-13 Alejandro Romanelli

This paper studies particle propagation in a one-dimensional inhomogeneous medium where the laws of motion are generated by chaotic and deterministic local maps. Assuming that the particle's initial location is random and uniformly…

Probability · Mathematics 2011-10-18 Lasse Leskelä , Mikko Stenlund

Quantum walks are considered in a one-dimensional random medium characterized by static or dynamic disorder. Quantum interference for static disorder can lead to Anderson localization which completely hinders the quantum walk and it is…

Quantum Physics · Physics 2009-11-13 Yue Yin , D. E. Katsanos , S. N. Evangelou

The effect of unitary noise on the discrete one-dimensional quantum walk is studied using computer simulations. For the noiseless quantum walk, starting at the origin (n=0) at time t=0, the position distribution Pt(n) at time t is very…

Quantum Physics · Physics 2009-11-10 Daniel Shapira , Ofer Biham , A. J. Bracken , Michelle Hackett

We investigate a connection between a property of the distribution and a conserved quantity for the reversible cellular automaton derived from a discrete-time quantum walk in one dimension. As a corollary, we give a detailed information of…

Quantum Physics · Physics 2009-11-10 Norio Konno , Kenichi Mitsuda , Takahiro Soshi , Hyun Jae Yoo

Propagation and interference of quantum-mechanical particles comprise an important part of elementary processes in quantum physics, and their essence can be modeled using a quantum walk, a mathematical concept that describes the motion of a…

Quantum Physics · Physics 2020-05-27 Masaya Tamura , Takashi Mukaiyama , Kenji Toyoda

We extend to the gamut of functional forms of the probability distribution of the time-dependent step-length a previous model dubbed Elephant Quantum Walk, which considers a uniform distribution and yields hyperballistic dynamics where the…

Quantum Physics · Physics 2020-07-21 Marcelo A. Pires , Giuseppe Di Molfetta , Sílvio M. Duarte Queirós

A quantum central limit theorem for a continuous-time quantum walk on a homogeneous tree is derived from quantum probability theory. As a consequence, a new type of limit theorems for another continuous-time walk introduced by the walk is…

Quantum Physics · Physics 2007-05-23 Norio Konno

We attempt to analyze a one-dimensional space-inhomogeneous quantum walk (QW) with one defect at the origin, which has two different quantum coins in positive and negative parts. We call the QW "the two-phase QW", which we treated…

Mathematical Physics · Physics 2017-05-02 Shimpei Endo , Takako Endo , Norio Konno , Etsuo Segawa , Masato Takei

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

Quantum walks are known to have nontrivial interactions with absorbing boundaries. In particular it has been shown that an absorbing boundary in the one dimensional quantum walk partially reflects information, as observed by absorption…

Quantum Physics · Physics 2020-03-11 Parker Kuklinski

Quantum random walk finds application in efficient quantum algorithms as well as in quantum network theory. Here we study the mixing time of a discrete quantum walk over a square lattice in presence percolation and decoherence. We consider…

Quantum Physics · Physics 2018-09-12 Arkaprabha Ghosal , Prasenjit Deb

Propagation in quantum walks is revisited by showing that very general 1D discrete-time quantum walks with time- and space-dependent coefficients can be described, at the continuous limit, by Dirac fermions coupled to electromagnetic…

Quantum Physics · Physics 2013-07-16 Fabrice Debbasch , Giuseppe Di Molfetta , David Espaze , Vincent Foulonneau

In this paper we present closed-form expressions for the wave function that governs the evolution of the discrete-time quantum walk on a line when the coin operator is arbitrary. The formulas were derived assuming that the walker can either…

Quantum Physics · Physics 2015-02-18 Miquel Montero

A discrete-time quantum walk (QW) is essentially a unitary operator driving the evolution of a single particle on the lattice. Some QWs have familiar physics PDEs as their continuum limit. Some slight generalization of them (allowing for…

Quantum Physics · Physics 2018-08-22 Pablo Arrighi , Giuseppe Di Molfetta , Stefano Facchini

We demonstrate a coined quantum walk over ten steps in a one-dimensional network of linear optical elements. By applying single-point phase defects, the translational symmetry of an ideal standard quantum walk is broken resulting in…

Quantum Physics · Physics 2014-05-27 P. Xue , H. Qin , B. Tang

Quantum walks have a host of applications, ranging from quantum computing to the simulation of biological systems. We present an intrinsically stable, deterministic implementation of discrete quantum walks with single photons in space. The…

Quantum Physics · Physics 2010-04-21 M. A. Broome , A. Fedrizzi , B. P. Lanyon , I. Kassal , A. Aspuru-Guzik , A. G. White