title: Observable entanglement measure for mixed quantum States.
abstract: We quantify an unknown mixed quantum state's entanglement by suitable, local parity measurements on its twofold copy. The associated observable qualifies as a generalized entanglement witness.
authors.affiliation: Department of Physics, Harvard University, 17 Oxford Street, Cambridge Massachusetts, USA.
authors.forename: Florian
authors.initials: F
authors.lastname: Mintert
authors.forename: Andreas
authors.initials: A
authors.lastname: Buchleitner