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Quantum walks obey unitary dynamics: they form closed quantum systems. The system becomes open if the walk suffers from imperfections represented as missing links on the underlying basic graph structure, described by dynamical percolation.…

Quantum Physics · Physics 2012-07-11 Bálint Kollár , Tamás Kiss , Jaroslav Novotný , Igor Jex

The dimensionality of the internal coin space of discrete-time quantum walks has a strong impact on the complexity and richness of the dynamics of quantum walkers. While two-dimensional coin operators are sufficient to define a certain…

The question of witnessing or quantifying nonclassicality of quantum systems has been addressed in various ways. For a given system or theory, we propose identifying it with the incompatibility of admissible states. We quantify the…

Quantum Physics · Physics 2013-12-05 Pavan Iyengar , G. N. Chandan , R. Srikanth

Due to the unitary evolution, quantum walks display different dynamical features from that of classical random walks. In contrast to this expectation, in this work, we show that extreme events can arise in unitary dynamics and its…

Quantum Physics · Physics 2025-02-27 Nisarg Vyas , M. S. Santhanam

We report on a discrete-time quantum walk that uses the momentum of ultra-cold rubidium-87 atoms as the walk space and two internal atomic states as the coin degree of freedom. Each step of the walk consists of a coin toss (a microwave…

Quantum Physics · Physics 2019-04-26 Siamak Dadras , Alexander Gresch , Caspar Groiseau , Sandro Wimberger , Gil S. Summy

The staggered quantum walk is a type of discrete-time quantum walk model without a coin which can be generated on a graph using particular partitions of the graph nodes. We design Hamiltonians for potential realization of the staggered…

Quantum Physics · Physics 2018-07-25 Jalil Khatibi Moqadam , Ali T. Rezakhani

The discrete time quantum walk defined as a quantum-mechanical analogue of the discrete time random walk have recently been attracted from various and interdisciplinary fields. In this review, the weak limit theorem, that is, the asymptotic…

Quantum Physics · Physics 2013-07-15 Yutaka Shikano

Continuous-time quantum walks (CTQWs) provide a valuable model for quantum transport, universal quantum computation and quantum spatial search, among others. Recently, the empowering role of new degrees of freedom in the Hamiltonian…

Quantum Physics · Physics 2022-03-23 Massimo Frigerio , Claudia Benedetti , Stefano Olivares , Matteo G. A. Paris

The subject of this paper is a kind of dynamical systems called quantum walks. We study one-dimensional homogeneous analytic quantum walks U. We explain how to identify the space of all the uniform intertwining operators between these…

Mathematical Physics · Physics 2019-02-08 Hiroki Sako

We clarify that coined quantum walk is determined by only the choice of local quantum coins. To do so, we characterize coined quantum walks on graph by disjoint Euler circles with respect to symmetric arcs. In this paper, we introduce a new…

Mathematical Physics · Physics 2014-05-08 Yusuke Higuchi , Norio Konno , Iwao Sato , Etsuo Segawa

It is shown that a standard one-dimensional coined discrete-time quantum walk can generate operationally admissible post-quantum correlations in a coin-position Bell scenario, without any modification of its unitary nearest-neighbor…

Quantum Physics · Physics 2026-05-08 Marcos C. de Oliveira

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

We introduce and study a class of discrete-time quantum walks on a one-dimensional lattice. In contrast to the standard homogeneous quantum walks, coin operators are inhomogeneous and depend on their positions in this class of models. The…

Quantum Physics · Physics 2010-09-17 Yutaka Shikano , Hosho Katsura

In this paper, we derive equations of motion for the normal-order, the symmetric-order and the antinormal-order quantum characteristic functions, applicable for general Hamiltonian systems. We do this by utilizing the `characteristic form'…

Quantum Physics · Physics 2008-05-02 Itay Hen , Amir Kalev

In the framework of quantum open systems, that is, simple quantum systems coupled to quantum baths, our aim is to characterize those actions of the quantum environment which give rise to dynamics dictated by classical noises. First, we…

Mathematical Physics · Physics 2019-07-23 Stephane Attal , Julien Deschamps , Clement Pellegrini

Quantum walks on graphs are ubiquitous in quantum computing finding a myriad of applications. Likewise, random walks on graphs are a fundamental building block for a large number of algorithms with diverse applications. While the…

Quantum Physics · Physics 2020-12-09 Matheus G. Andrade , Franklin Marquezino , Daniel R. Figueiredo

Dynamical evolution of systems with sparse Hamiltonians can always be recognized as continuous time quantum walks (CTQWs) on graphs. In this paper, we analyze the short time asymptotics of CTQWs. In recent studies, it was shown that for the…

Quantum Physics · Physics 2019-12-25 Balázs Endre Szigeti , Gábor Homa , Zoltán Zimborás , Norbert Barankai

We explore a discrete-time, coined quantum walk on a quantum network where the coherent superposition of walker-moves originates from the unitary interaction of the walker-coin with the qubit degrees of freedom in the quantum network. The…

Quantum Physics · Physics 2024-06-04 Jigyen Bhavsar , Shashank Shekhar , Siddhartha Santra

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

We study a class of discrete-time quantum walks with inhomogeneous coins defined in [Y. Shikano and H. Katsura, Phys. Rev. E {\bf 82}, 031122 (2010)]. We establish symmetry properties of the spectrum of the evolution operator, which…

Quantum Physics · Physics 2011-10-24 Yutaka Shikano , Hosho Katsura