Measuring quantum entanglement without prior state reconstruction

被引：106

作者：

Horodecki, P ^{[1
]}

机构：

[1] Gdansk Univ Technol, Fac Appl Phys & Math, PL-80952 Gdansk, Poland

来源：

PHYSICAL REVIEW LETTERS | 2003年 / 90卷 / 16期

关键词：

D O I：

10.1103/PhysRevLett.90.167901

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

It is shown that, despite strong nonlinearity, entanglement of formation of a two-qubit state can be measured without prior state reconstruction. Collective measurements on a small number of copies are provided that allow one to determine quantum concurrence via estimation of only four parameters. It is also pointed out that another entanglement measure based on so-called "negativity" can also be measured in a similar way. The result is related to the general problem: What kind of information can be extracted efficiently from an unknown quantum state?

引用

页数：4

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