Issue
EPL
Volume 78, Number 4, May 2007
Article Number 40002
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/78/40002
Published online 03 May 2007
EPL, 78 (2007) 40002
DOI: 10.1209/0295-5075/78/40002

Experimental entanglement quantification and verification via uncertainty relations

Zhi-Wei Wang, Yun-Feng Huang, Xi-Feng Ren, Yong-Sheng Zhang and Guang-Can Guo

Key Laboratory of Quantum Information, University of Science and Technology of China, CAS - Hefei 230026, PRC

sdzzwzw@mail.ustc.edu.cn
hyf@ustc.edu.cn

received 11 January 2007; accepted in final form 3 April 2007; published May 2007
published online 3 May 2007

Abstract
We report on experimental studies on entanglement quantification and verification based on uncertainty relations for systems consisting of two qubits. The new proposed measure is shown to be invariant under local unitary transformations, by which entanglement quantification is implemented for two-qubit pure states. The nonlocal uncertainty relations for two-qubit pure states are also used for entanglement verification which serves as a basic proposition and promise to be a good choice for verification of multipartite entanglement.

PACS
03.67.Mn - Entanglement production, characterization, and manipulation .
42.50.Dv - Nonclassical states of the electromagnetic field, including entangled photon states; quantum state engineering and measurements .
42.65.Lm - Parametric down conversion and production of entangled photons .

© Europhysics Letters Association 2007