English
Related papers

Related papers: Invariance in quantum walks with time-dependent co…

200 papers

We introduce the driven discrete time quantum walk, where walkers are added during the walk instead of only at the beginning. This leads to interference in walker number and very different dynamics when compared to the original quantum…

Quantum Physics · Physics 2016-09-01 Craig S. Hamilton , Sonja Barkhofen , Linda Sansoni , Igor Jex , Christine Silberhorn

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

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

Coherent evolution governs the behaviour of all quantum systems, but in nature it is often subjected to influence of a classical environment. For analysing quantum transport phenomena quantum walks emerge as suitable model systems. In…

This letter treats the quantum random walk on the line determined by a 2 times 2 unitary matrix U. A combinatorial expression for the mth moment of the quantum random walk is presented by using 4 matrices, P, Q, R and S given by U. The…

Quantum Physics · Physics 2007-05-23 Norio Konno

Quantum walks are dynamic systems with a wide range of applications in quantum computation and quantum simulation of analog systems, therefore it is of common interest to understand what changes from an isolated process to one embedded in…

Quantum Physics · Physics 2022-12-19 Luísa Toledo Tude , Marcos C. de Oliveira

We report the experimental detection of bulk topological invariants in nonunitary discrete-time quantum walks with single photons. The nonunitarity of the quantum dynamics is enforced by periodically performing partial measurements on the…

Quantum Physics · Physics 2017-10-02 Xiang Zhan , Lei Xiao , Zhihao Bian , Kunkun Wang , Xingze Qiu , Barry C. Sanders , Wei Yi , Peng Xue

This work deals with both instantaneous uniform mixing property and temporal standard deviation for continuous-time quantum random walks on circles in order to study their fluctuations comparing with discrete-time quantum random walks, and…

Quantum Physics · Physics 2007-05-23 Norio Inui , Koichiro Kasahara , Yoshinao Konishi , Norio Konno

Open quantum walks often lead to a classical asymptotic behavior. Here, we look for a simple open quantum walk whose asymptotic behavior can be non-classical. We consider a discrete-time quantum walk on n-cycle subject to a random…

Quantum Physics · Physics 2019-11-27 Adam S. Sajna , Tomasz P. Polak , Antoni Wojcik , Pawel Kurzynski

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

The discrete-time quantum walk dynamics can be generated by a time-dependent Hamiltonian, repeatedly switching between the coin and the shift generators. We change the model and consider the case where the Hamiltonian is time-independent,…

Quantum Physics · Physics 2022-03-03 Jalil Khatibi Moqadam , Marcos Cesar de Oliveira

Discrete-time quantum walk evolve by a unitary operator which involves two operators a conditional shift in position space and a coin operator. This operator entangles the coin and position degrees of freedom of the walker. In this paper,…

Quantum Physics · Physics 2012-07-10 S. Salimi , R. Yosefjani

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

Quantum walks are powerful tools not only to construct the quantum speedup algorithms but also to describe specific models in physical processes. Furthermore, the discrete time quantum walk has been experimentally realized in various…

Quantum Physics · Physics 2010-06-29 Yutaka Shikano , Kota Chisaki , Etsuo Segawa , Norio Konno

We prove an invariance principle for continuous-time random walks in a dynamically averaging environment on $\mathbb Z$. In the beginning, the conductances may fluctuate substantially, but we assume that as time proceeds, the fluctuations…

Probability · Mathematics 2020-09-24 Stein Andreas Bethuelsen , Christian Hirsch , Christian Mönch

We present a new scheme for a discrete-time quantum walk on two- and three-dimensional lattices using a two-state particle. We use different Pauli basis as translational eigestates for different axis and show that the coin operation, which…

Quantum Physics · Physics 2015-03-19 C. M. Chandrashekar

When confined to a topological environment consisting of a cycle coupled with a half-line, quantum walks exhibit long-term statistical tendencies which differ dramatically from the tendencies of classical random walks in the same…

Quantum Physics · Physics 2015-06-08 Forrest Ingram-Johnson , Chaobin Liu , Nelson Petulante

Quantum walk acts obviously different from its classical counterpart, but decoherence will lessen and close the gap between them. To understand this process, it is necessary to investigate the evolution of quantum walk under different…

Quantum Physics · Physics 2015-06-04 Peng Xue , Yongsheng Zhang

We present a generalized version of the discrete time quantum walk, using the SU(2) operation as the quantum coin. By varying the coin parameters, the quantum walk can be optimized for maximum variance subject to the functional form…

Quantum Physics · Physics 2009-11-13 C. M. Chandrashekar , R. Srikanth , Raymond Laflamme

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