English
Related papers

Related papers: One-dimensional quantum walks with one defect

200 papers

Quantum random walks have been much studied recently, largely due to their highly nonclassical behavior. In this paper, we study one possible route to classical behavior for the discrete quantum random walk on the line: the use of multiple…

Quantum Physics · Physics 2009-11-07 Todd A. Brun , Hilary A. Carteret , Andris Ambainis

In this expository note, we discuss spatially inhomogeneous quantum walks in one dimension and describe a genre of mathematical methods that enables one to translate information about the time-independent eigenvalue equation for the unitary…

Spectral Theory · Mathematics 2017-04-25 Jake Fillman

We characterize quantumness of the so-called quantum walks (whose dynamics is governed by quantum mechanics) by introducing two computable measures which are stronger than the variance of the walker's position probability distribution. The…

Quantum Physics · Physics 2018-10-09 F. Shahbeigi , S. J. Akhtarshenas , A. T. Rezakhani

Quantum walks (QWs) exhibit different properties compared with classical random walks (RWs), most notably by linear spreading and localization. In the meantime, random walks that replicate quantum walks, which we refer to as…

Mathematical Physics · Physics 2022-11-01 Tomoki Yamagami , Etsuo Segawa , Nicolas Chauvet , André Röhm , Ryoichi Horisaki , Makoto Naruse

We study a class of symmetric quantum walks on Hamming graphs, where the distance between vertices specifies the transition probability. A special model is the simple quantum walk on the hypercube, which has been discussed in the…

Quantum Physics · Physics 2026-03-25 Robert Griffiths , Shuhei Mano

We investigate the quantum versions of a one-dimensional random walk, whose corresponding Markov Chain is of order 2. This corresponds to the walk having a memory of up to two previous steps. We derive the amplitudes and probabilities for…

Quantum Physics · Physics 2010-05-02 Michael McGettrick

We introduce a continuous-time quantum walk on an ultrametric space corresponding to the set of p-adic integers and compute its time-averaged probability distribution. It is shown that localization occurs for any location of the ultrametric…

Quantum Physics · Physics 2009-03-24 Norio Konno

Quantum walks, both discrete (coined) and continuous time, form the basis of several quantum algorithms and have been used to model processes such as transport in spin chains and quantum chemistry. The enhanced spreading and mixing…

Quantum Physics · Physics 2010-12-10 Godfrey Leung , Paul Knott , Joe Bailey , Viv Kendon

Quantum walk has been regarded as a primitive to universal quantum computation. By using the operations required to describe the single particle discrete-time quantum walk on a position space we demonstrate the realization of the universal…

Quantum Physics · Physics 2021-06-16 Shivani Singh , Prateek Chawla , Anupam Sarkar , C. M. Chandrashekar

Quantum Stochastic Walks (QSW) allow for a generalization of both quantum and classical random walks by describing the dynamic evolution of an open quantum system on a network, with nodes corresponding to quantum states of a fixed basis. We…

Quantum Physics · Physics 2020-03-31 Nicola Dalla Pozza , Filippo Caruso

The first general analytic solutions for the one-dimensional walk in position and momentum space are derived. These solutions reveal, among other things, new symmetry features of quantum walk probability densities and further insight into…

Quantum Physics · Physics 2007-05-23 Ian Fuss , Lang White , Peter Sherman , Sanjeev Naguleswaran

We propose a new theory on a relation between diffusive and coherent nature in one dimensional wave mechanics based on a quantum walk. It is known that the quantum walk in homogeneous matrices provides the coherent property of wave…

Quantum Physics · Physics 2017-06-28 Yusuke Ide , Norio Konno , Shigeki Matsutani , Hideo Mitsuhashi

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

We construct a new type of quantum walks on simplicial complexes as a natural extension of the well-known Szegedy walk on graphs. One can numerically observe that our proposing quantum walks possess linear spreading and localization as in…

Mathematical Physics · Physics 2015-08-05 Kaname Matsue , Osamu Ogurisu , Etsuo Segawa

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

Quantum walks have been shown to have impressive transport properties compared to classical random walks. However, imperfections in the quantum walk algorithm can destroy any quantum mechanical speed-up due to Anderson localization. We…

Quantum Physics · Physics 2013-05-30 Steven R. Jackson , Teng Jian Khoo , Frederick W. Strauch

Quantum walks can reconstruct quantum algorithms for quantum computation, where the precise controls of quantum state transfers between arbitrary distant sites are required. Here, we investigate quantum walks using a periodically…

Quantum Physics · Physics 2020-04-06 Haruna Katayama , Noriyuki Hatakenaka , Toshiyuki Fujii

Quantum walks have by now been realized in a large variety of different physical settings. In some of these, particularly with trapped ions, the walk is implemented in phase space, where the corresponding position states are not orthogonal.…

Quantum Physics · Physics 2014-04-02 R. Matjeschk , A. Ahlbrecht , M. Enderlein , Ch. Cedzich , A. H. Werner , M. Keyl , T. Schaetz , R. F. Werner

We consider a new model of quantum walk on a one-dimensional momentum space that includes both discrete jumps and continuous drift. Its time evolution has two stages; a Markov diffusion followed by localized dynamics. As in the well known…

Quantum Physics · Physics 2009-11-10 A. Romanelli , A. Auyuanet , R. Siri , G. Abal , R. Donangelo

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