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Quantum walks are known to propagate quadratically faster than their classical counterparts and are used to model dynamics in various quantum systems. The spread of the quantum walk in position space shows anomalous diffusion behavior. By…

Quantum Physics · Physics 2022-05-24 Abhaya S. Hegde , C. M. Chandrashekar

A classical lazy random walk on cycles is known to mix to the uniform distribution. In contrast, we show that a continuous-time quantum walk on cycles exhibit strong non-uniform mixing properties. Our results include the following: - The…

Using the concept of von Neumann entropy, we quantify the information content of the various components of the quantum walk system, including the mutual information between its subsystems (coin and position) and use it to give a precise…

Mathematical Physics · Physics 2011-10-11 Clement Ampadu

The discrete-time quantum walk is a quantum counterpart of the random walk. It is expected that the model plays important roles in the quantum field. In the quantum information theory, entanglement is a key resource. We use the von Neumann…

Quantum Physics · Physics 2011-09-21 Yusuke Ide , Norio Konno , Takuya Machida

We show that quantum walks interpolate between a coherent `wave walk' and a random walk depending on how strongly the walker's coin state is measured; i.e., the quantum walk exhibits the quintessentially quantum property of complementarity,…

Quantum Physics · Physics 2009-11-10 Viv Kendon , Barry C. Sanders

Decoherence transforms a ballistic quantum walk into a diffusive classical random walk. After each step the environment measures the particle's path and the outside world gets to know the which-way information. The relation between the…

Quantum Physics · Physics 2018-12-04 Mikolaj Lewandowski , Tomasz Kopyciuk , Pawel Kurzynski

There are presently two models for quantum walks on graphs. The "coined" walk uses discrete time steps, and contains, besides the particle making the walk, a second quantum system, the coin, that determines the direction in which the…

Quantum Physics · Physics 2009-11-10 Mark Hillery , Janos Bergou , Edgar Feldman

The position density of a "particle" performing a continuous-time quantum walk on the integer lattice, viewed on length scales inversely proportional to the time t, converges (as t tends to infinity) to a probability distribution that…

Quantum Physics · Physics 2013-05-29 Alex D. Gottlieb

Recently, it has been shown that one-dimensional quantum walks can mix more quickly than classical random walks, suggesting that quantum Monte Carlo algorithms can outperform their classical counterparts. We study two quantum walks on the…

Quantum Physics · Physics 2007-05-23 Cristopher Moore , Alexander Russell

We study a 2-D disordered time-discrete quantum walk based on 1-D `generalized elephant quantum walk' where an entangling coin operator is assumed and which paves the way to a new set of properties. We show that considering a given disorder…

We introduce the Peierls substitution to a two-dimensional discrete-time quantum walk on a square lattice to examine the spreading dynamics and the coin-position entanglement in the presence of an artificial gauge field. We use the ratio of…

Quantum Physics · Physics 2015-10-28 İ. Yalçınkaya , Z. Gedik

A number of recent studies have investigated the introduction of decoherence in quantum walks and the resulting transition to classical random walks. Interestingly, it has been shown that algorithmic properties of quantum walks with…

Quantum Physics · Physics 2016-01-19 Andrea Torsello , Luca Rossi

We present analytical treatment of quantum walks on multidimensional hyper-cycle graphs. We derive the analytical expression of the probability distribution for strong and weak decoherence regimes. Upper bound to mixing time is obtained.

Quantum Physics · Physics 2007-05-23 Dmitry Solenov , Leonid Fedichkin

Consider a discrete-time quantum walk on the $N$-cycle governed by the following condition: at every time step of the walk, the option persists, with probability $p$, of exercising a projective measurement on the coin degree of freedom. For…

Quantum Physics · Physics 2010-11-16 Chaobin Liu , Nelson Petulante

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

We study the localization properties, energy spectra and coin-position entanglement of the aperiodic discrete-time quantum walks. The aperiodicity is described by spatially dependent quantum coins distributed on the lattice, whose…

Quantum Physics · Physics 2019-09-11 A. R. C. Buarque , W. S. Dias

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

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

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

We put forward a new, versatile and highly-scalable experimental setup for the realization of discrete two-dimensional quantum random walks with a single-qubit coin and tunable degree of decoherence. The proposed scheme makes use of a small…

Quantum Physics · Physics 2012-11-29 Jiří Svozilík , Roberto de Jesús León-Montiel , Juan P. Torres