Field-induced order-disorder transition in antiferromagnetic BaCo(2)V(2)O(8) driven by a softening of spinon excitation.
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).
Kimura
S
S
KYOKUGEN, Osaka University, Machikaneyama 1-3, Toyanaka, Japan.
Yashiro
H
H
Okunishi
K
K
Hagiwara
M
M
He
Z
Z
Kindo
K
K
Taniyama
T
T
Itoh
M
M
D060526:Magnetic Fields; D008962:Models, Theoretical; D044367:Phase Transition