title: Persistent entanglement in arrays of interacting particles.
abstract: We study the entanglement properties of a class of N-qubit quantum states that are generated in arrays of qubits with an Ising-type interaction. These states contain a large amount of entanglement as given by their Schmidt measure. They also have a high persistency of entanglement which means that approximately N/2 qubits have to be measured to disentangle the state. These states can be regarded as an entanglement resource since one can generate a family of other multiparticle entangled states such as the generalized Greenberger-Horne-Zeilinger states of <N/2 qubits by simple measurements and classical communication.
authors.affiliation: Sektion Physik, Ludwig-Maximilians-Universität, Theresienstrasse 37, D-80333 München, Germany.
authors.forename: H J
authors.initials: HJ
authors.lastname: Briegel
authors.forename: R
authors.initials: R
authors.lastname: Raussendorf