title: Quantum computational renormalization in the Haldane phase.
abstract: Single-spin measurements on the ground state of an interacting spin lattice can be used to perform a quantum computation. We show how such measurements can mimic renormalization group transformations and remove the short-ranged variations of the state that can reduce the fidelity of a computation. This suggests that the quantum computational ability of a spin lattice could be a robust property of a quantum phase. We illustrate our idea with the ground state of a rotationally invariant spin-1 chain, which can serve as a quantum computational wire not only at the Affleck-Kennedy-Lieb-Tasaki point, but within the Haldane phase.
authors.affiliation: School of Physics, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Bartlett
authors.forename: Gavin K
authors.initials: GK
authors.lastname: Brennen
authors.forename: Akimasa
authors.initials: A
authors.lastname: Miyake
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Renes