title: Entanglement detection by local orthogonal observables.
abstract: We propose a family of entanglement witnesses and corresponding positive maps that are not completely positive based on local orthogonal observables. As applications the entanglement witness of a 3x3 bound entangled state [P. Horodecki, Phys. Lett. A 232, 333 (1997)] is explicitly constructed and a family of dxd bound entangled states is introduced, whose entanglement can be detected by permuting local orthogonal observables. The proposed criterion of separability can be physically realized by measuring a Hermitian correlation matrix of local orthogonal observables.
authors.affiliation: Department of Modern Physics & Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
authors.forename: Sixia
authors.initials: S
authors.lastname: Yu
authors.forename: Nai-le
authors.initials: NL
authors.lastname: Liu