title: Field-induced order-disorder transition in antiferromagnetic BaCo(2)V(2)O(8) driven by a softening of spinon excitation.
abstract: High field magnetization and ESR measurements on the quasi-one-dimensional (1D) antiferromagnet BaCo(2)V(2)O(8) have been performed in magnetic fields up to 50 T along the chain. The experimental results are explained well in terms of a 1D S=1/2 antiferromagnetic XXZ model in longitudinal fields. We show that the quantum phase transition from the Néel ordered phase to the spin liquid one in the model is responsible for a peculiar order to disorder transition in BaCo(2)V(2)O(8).
authors.affiliation: KYOKUGEN, Osaka University, Machikaneyama 1-3, Toyanaka, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: Yashiro
authors.forename: K
authors.initials: K
authors.lastname: Okunishi
authors.forename: M
authors.initials: M
authors.lastname: Hagiwara
authors.forename: Z
authors.initials: Z
authors.lastname: He
authors.forename: K
authors.initials: K
authors.lastname: Kindo
authors.forename: T
authors.initials: T
authors.lastname: Taniyama
authors.forename: M
authors.initials: M
authors.lastname: Itoh
mesh_terms: D060526:Magnetic Fields; D008962:Models, Theoretical; D044367:Phase Transition