title: Measurement-based teleportation along quantum spin chains.
abstract: We examine the teleportation of an unknown spin-1/2 quantum state along a quantum spin chain with an even number of sites. Our protocol, using a sequence of Bell measurements, may be viewed as an iterated version of the 2-qubit protocol of C. H. Bennett et al. [Phys. Rev. Lett. 70, 1895 (1993)]. A decomposition of the Hilbert space of the spin chain into 4 vector spaces, called Bell subspaces, is given. It is established that any state from a Bell subspace may be used as a channel to perform unit fidelity teleportation. The space of all spin-0 many-body states, which includes the ground states of many known antiferromagnetic systems, belongs to a common Bell subspace. A channel-dependent teleportation parameter [symbol: see text] is introduced, and a bound on the teleportation fidelity is given in terms of [symbol: see text].
authors.affiliation: Department of Physics, University of Queensland, Queensland QLD 4072, Australia. jpb@physics.uq.edu.au
authors.forename: J P
authors.initials: JP
authors.lastname: Barjaktarevic
authors.forename: R H
authors.initials: RH
authors.lastname: McKenzie
authors.forename: J
authors.initials: J
authors.lastname: Links
authors.forename: G J
authors.initials: GJ
authors.lastname: Milburn