Direct method for measuring and witnessing quantum entanglement of arbitrary two-qubit states through Hong-Ou-Mandel interference

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F17%3A73581174" target="_blank" >RIV/61989592:15310/17:73581174 - isvavai.cz</a>

Result on the web

<a href="https://journals.aps.org/pra/pdf/10.1103/PhysRevA.95.022331" target="_blank" >https://journals.aps.org/pra/pdf/10.1103/PhysRevA.95.022331</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevA.95.022331" target="_blank" >10.1103/PhysRevA.95.022331</a>

Result language

angličtina

Original language name

Direct method for measuring and witnessing quantum entanglement of arbitrary two-qubit states through Hong-Ou-Mandel interference

Original language description

We describe a direct method for experimental determination of the negativity of an arbitrary two-qubit state with 11 measurements performed on multiple copies of the two-qubit system. Our method is based on the experimentally accessible sequences of singlet projections performed on up to four qubit pairs. In particular, our method permits the application of the Peres-Horodecki separability criterion to an arbitrary two-qubit state. We explicitly demonstrate that measuring entanglement in terms of negativity requires three measurements more than detecting two-qubit entanglement. The reported minimal set of interferometric measurements provides a complete description of bipartite quantum entanglement in terms of two-photon interference. This set is smaller than the set of 15 measurements needed to perform a complete quantum state tomography of an arbitrary two-qubit system. Finally, we demonstrate that the set of nine Makhlin&apos;s invariants needed to express the negativity can be measured by performing 13 multicopy projections. We demonstrate both that these invariants are a useful theoretical concept for designing specialized quantum interferometers and that their direct measurement within the framework of linear optics does not require performing complete quantum state tomography.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10306 - Optics (including laser optics and quantum optics)

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

2017

Confidentiality

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

Name of the periodical

Physical Review A

ISSN

2469-9926

e-ISSN

—

Volume of the periodical

95

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

7

Pages from-to

"022331-1"-"022331-7"

UT code for WoS article

000394653900001

EID of the result in the Scopus database

2-s2.0-85013780841