How to determine the existence of the common entanglement witnesses for some entangled states
Entanglement witnesses(EW) are non-positive Hermitian operators which can detect the presence of entanglement. Let Eρ denote the set of entanglement witnesses which can detect the entangled state ρ. In this paper, we consider the relationship between Eρ1 and Eρ2. And the main results are three sufficient and necessary conditions. 1) Eρ1 =Eρ2 if and only if ρ1 =ρ2. 2)Eρ1 (∪) Eρ2 if and only if there exist 0 ≤ε≤ 1 and a separable state ρsep such that p1 =ερ2 + (1-ε)ρsep. 3) Eρ1 ∩ Eρ2 ≠φ if and only if there exists 0 ≤λ≤ 1 such that λρ1 + (1-λ)ρ2 is a separable state.
Entangled state entanglement witness
Yu-Chun Wu Guang-Can Guo
Key Laboratory of Quantum Information, USTC, CAS
国际会议
Asian Conference on Quantum Onformation Science 2006(2006亚洲量子信息大会)
北京
英文
158-159
2006-09-01（万方平台首次上网日期，不代表论文的发表时间）