Determining the existence of the common entanglement witnesses for some entangled states

Journal Article · Tue May 15 04:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.75.052333· OSTI ID:20982502

Wu, Yu-Chun; Guo, Guang-Can ^[1]

---

1. Laboratory of Quantum Information, University of Science and Technology of China, 230026 Hefei Anhui (China)

Entanglement witnesses (EWs) are nonpositive Hermitian operators which can detect the presence of entanglement. In this paper, we prove that for a given pair of entangled states {rho}{sub 1} and {rho}{sub 2} an EW, W, common to both of them exists if and only if for all 0{<=}{lambda}{<=}1, {lambda}{rho}{sub 1}+(1-{lambda}){rho}{sub 2} is an entangled state. Based on this result, we find a sufficient condition for the presence of entanglement. We then show that an EW which can detect all bell states simultaneously does not exist.

• OSTI ID: 20982502
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 75; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BELL THEOREM
HERMITIAN OPERATORS
INFORMATION THEORY
QUANTUM ENTANGLEMENT
QUANTUM INFORMATION
QUANTUM MECHANICS