Percolation assisted excitation transport in discrete-time quantum walks

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F16%3A00300542" target="_blank" >RIV/68407700:21340/16:00300542 - isvavai.cz</a>

Result on the web

<a href="http://iopscience.iop.org/article/10.1088/1367-2630/18/2/023040/meta;jsessionid=D5616285246B76C4E5B71AF0C884A750.c1.iopscience.cld.iop.org" target="_blank" >http://iopscience.iop.org/article/10.1088/1367-2630/18/2/023040/meta;jsessionid=D5616285246B76C4E5B71AF0C884A750.c1.iopscience.cld.iop.org</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1367-2630/18/2/023040" target="_blank" >10.1088/1367-2630/18/2/023040</a>

Result language

angličtina

Original language name

Percolation assisted excitation transport in discrete-time quantum walks

Original language description

Coherent transport of excitations along chains of coupled quantum systems represents an interesting problem with a number of applications ranging from quantum optics to solar cell technology. A convenient tool for studying such processes are quantum walks. They allow us to determine all the process features in a quantitative way. We study the survival probability and the transport efficiency on a simple, highly symmetric graph represented by a ring. The propagation of excitation is modeled by a discrete-time (coined) quantum walk. For a two-state quantum walk, where the excitation (walker) has to leave its actual position to the neighboring sites, the survival probability decays exponentially and the transport efficiency is unity. The decay rate of the survival probability can be estimated using the leading eigenvalue of the evolution operator. However, if the excitation is allowed to stay at its present position, i.e. the propagation is modeled by a lazy quantum walk, then part of the wave-packet can be trapped in the vicinity of the origin and never reaches the sink. In such a case, the survival probability does not vanish and the excitation transport is not efficient. The dependency of the transport efficiency on the initial state is determined. Nevertheless, we show that for some lazy quantum walks dynamical, percolations of the ring eliminate the trapping effect and efficient excitation transport can be achieved.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BE - Theoretical physics

OECD FORD branch

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Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

New Journal of Physics

ISSN

1367-2630

e-ISSN

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Volume of the periodical

18

Issue of the periodical within the volume

February

Country of publishing house

GB - UNITED KINGDOM

Number of pages

13

Pages from-to

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UT code for WoS article

000372456300002

EID of the result in the Scopus database

2-s2.0-84960153582