Optimal two-qubit tomography based on local and global measurements: Maximal robustness against errors as described by condition numbers

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F14%3A33151852" target="_blank" >RIV/61989592:15310/14:33151852 - isvavai.cz</a>

Result on the web

<a href="http://journals.aps.org/pra/pdf/10.1103/PhysRevA.90.062123" target="_blank" >http://journals.aps.org/pra/pdf/10.1103/PhysRevA.90.062123</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevA.90.062123" target="_blank" >10.1103/PhysRevA.90.062123</a>

Result language

angličtina

Original language name

Optimal two-qubit tomography based on local and global measurements: Maximal robustness against errors as described by condition numbers

Original language description

We present an error analysis of various tomographic protocols based on the linear inversion for the reconstruction of an unknown two-qubit state. We solve the problem of finding a tomographic protocol which is the most robust against errors in terms of the lowest value (i.e., equal to 1) of a condition number, as required by the Gastinel-Kahan theorem. In contrast, standard tomographic protocols, including those based on mutually unbiased bases, are nonoptimal for determining all the 16 elements of an unknown two-qubit density matrix. Our method is based on the measurements of the 16 generalized Pauli operators, where twelve of them can be locally measured, and the other four require nonlocal Bell measurements. Our method corresponds to selectively measuring, one by one, all the real and imaginary elements of an unknown two-qubit density matrix. We describe two experimentally feasible setups of this protocol for the optimal reconstruction of two photons in an unknown polarization state

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

BH - Optics, masers and lasers

OECD FORD branch

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Project

<a href="/en/project/LO1305" target="_blank" >LO1305: Development of the center of advanced technologies and materials</a><br>

Continuities

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

Publication year

2014

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

90

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

12

Pages from-to

"062123-1"-"062123-12"

UT code for WoS article

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EID of the result in the Scopus database

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