Concurrence versus purity: Influence of local channels on Bell states of two qubits

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14330%2F05%3A00013049" target="_blank" >RIV/00216224:14330/05:00013049 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Concurrence versus purity: Influence of local channels on Bell states of two qubits

Original language description

We analyze how a maximally entangled state of two qubits (e.g., the singlet $psi_s$) is affected by the action of local channels described by completely positive maps $E$. We analyze the concurrence and the purity of states $rho_E=E otimes I_psi_s$. Using the concurrence-versus-purity phase diagram we characterize local channels $E$ by their action on the singlet state $psi_s$. We specify a region of the concurrence-versus-purity diagram that is achievable from the singlet state via the action of unital channels. We show that even the most general (including nonunital) local channels acting just on a single qubit of the original singlet state cannot generate the maximally entangled mixed states. We study in detail various time evolutions of the original singlet state induced by local Markovian semigroups. We show that the decoherence process is represented in the concurrence-versus-purity diagram by a line that forms the lower bound of the achievable region for unital maps. On the oth

Czech name

Míra entanglování concurrence versus čistota: vliv lokálních kanálů na Bellovy stavy o dvou qubitech

Czech description

Analýza vlivu lokální dynamiky na maximálně entanglované stavy, analýza procesu dekoherence, exponenciálních rozpadů, homogenizace kvantových bitů a jejich dopad na snižování entanglování.

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

<a href="/en/project/GA201%2F04%2F1153" target="_blank" >GA201/04/1153: Quantum resources and primitives</a><br>

Continuities

Z - Vyzkumny zamer (s odkazem do CEZ)

Publication year

2005

Confidentiality

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

Name of the periodical

Physical Review A

ISSN

1050-2947

e-ISSN

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Volume of the periodical

Vol. 72

Issue of the periodical within the volume

No. 5

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

"A052325"

UT code for WoS article

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EID of the result in the Scopus database

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