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We present a comprehensive classification of one-dimensional coined quantum walks on the infinite line, focusing on the spatial probability distributions they induce. Building on prior results, we identify all initial coin states that lead…

Quantum Physics · Physics 2025-08-01 Lukas Hantzko , Lennart Binkowski

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

The purpose of this paper is to show that: when a single particle moving under 3-proper time (three-dimensional time), the trajectories of a classical particle are equivalent to a quantum field with spin. Three-proper time models are built…

Quantum Physics · Physics 2007-05-23 Xiaodong Chen

The physics of quantum walks on graphs is formulated in Hamiltonian language, both for simple quantum walks and for composite walks, where extra discrete degrees of freedom live at each node of the graph. It is shown how to map between…

Quantum Physics · Physics 2009-11-13 Andrew P. Hines , P. C. E. Stamp

The development of quantum algorithms based on quantum versions of random walks is placed in the context of the emerging field of quantum computing. Constructing a suitable quantum version of a random walk is not trivial: pure quantum…

Quantum Physics · Physics 2007-05-23 Viv Kendon

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

Quantum walks have emerged as an interesting alternative to the usual circuit model for quantum computing. While still universal for quantum computing, the quantum walk model has very different physical requirements, which lends itself more…

Quantum Physics · Physics 2015-05-19 Peter P. Rohde , Andreas Schreiber , Martin Stefanak , Igor Jex , Christine Silberhorn

We analyze the quantum walk in higher spatial dimensions and compare classical and quantum spreading as a function of time. Tensor products of Hadamard transformations and the discrete Fourier transform arise as natural extensions of the…

Quantum Physics · Physics 2007-05-23 Troy D. Mackay , Stephen D. Bartlett , Leigh T. Stephenson , Barry C. Sanders

Hitting times are the average time it takes a walk to reach a given final vertex from a given starting vertex. The hitting time for a classical random walk on a connected graph will always be finite. We show that, by contrast, quantum walks…

Quantum Physics · Physics 2009-11-13 Hari Krovi , Todd A. Brun

Quantum versions of random walks have diverse applications that are motivating experimental implementations as well as theoretical studies. However, the main impetus behind this interest is their use in quantum algorithms, which have always…

Quantum Physics · Physics 2011-07-20 Viv Kendon

Quantum walks are well-known for their ballistic dispersion, traveling $\Theta(t)$ away in $t$ steps, which is quadratically faster than a classical random walk's diffusive spreading. In physical implementations of the walk, however, the…

Quantum Physics · Physics 2016-01-25 Thomas G. Wong

A quantum version of the action principle is considered in the case of a free relativistic particle. The classical limit of the quantum action is obtained.

Quantum Physics · Physics 2008-12-09 Natalia Gorobey , Alexander Lukyanenko

The most elementary quantum walk is characterized by a 2-dimensional unitary coin flip matrix, which can be parameterized by 4 real variables. The influence of the choice of the coin flip matrix on the time evolution operator is analysed in…

Quantum Physics · Physics 2015-01-30 Lauri Lehman

Quantum walks have emerged as an interesting approach to quantum information processing, exhibiting many unique properties compared to the analogous classical random walk. Here we introduce a model for a discrete-time quantum walk with…

Quantum Physics · Physics 2013-05-08 Peter P. Rohde , Gavin K. Brennen , Alexei Gilchrist

We provide an explanation of recent experimental results of Xue et al., where full revivals in a time-dependent quantum walk model with a periodically changing coin are found. Using methods originally developed for "electric" walks with a…

Quantum Physics · Physics 2016-04-08 C. Cedzich , R. F. Werner

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 probability distributions of discrete-time quantum walks have been often investigated, and many interesting properties of them have been discovered. The probability that the walker can be find at a position is defined by diagonal…

Quantum Physics · Physics 2013-04-01 Takuya Machida

On the basis of extensive numerical studies it is argued that there are strong analogies between the probabilistic behavior of quantum systems defined by Hermitian Hamiltonians and the deterministic behavior of classical mechanical systems…

High Energy Physics - Theory · Physics 2010-05-28 Carl M. Bender , Dorje C. Brody , Daniel W. Hook

The control of quantum walk is made particularly transparent when the initial state is expressed in terms of the eigenstates of the coin operator. We show that the group-velocity density acquires a much simpler form when expressed in this…

Quantum Physics · Physics 2014-05-30 Martin Stefanak , Igor Jex

This paper continues the study of large time behavior of a nonlinear quantum walk begun in arXiv:1801.03214. In this paper, we provide a weak limit theorem for the distribution of the nonlinear quantum walk. The proof is based on the…

Mathematical Physics · Physics 2018-01-23 Masaya Maeda , Hironobu Sasaki , Etsuo Segawa , Akito Suzuki , Kanako Suzuki