title: Magnetic spin ladder (C5H12N)2CuBr4: high-field magnetization and scaling near quantum criticality.
abstract: The magnetization, M(H< or =30 T,0.7< or =T< or =300 K), of (C5H12N)2CuBr4 has been used to identify this system as an S = 1/2 Heisenberg two-leg ladder in the strong-coupling limit, J( perpendicular) = 13.3 K and J( parallel) = 3.8 K, with H(c1) = 6.6 T and H(c2) = 14.6 T. An inflection point in M(H,T = 0.7 K) at half saturation, M(s)/2, is described by an effective XXZ chain. The data exhibit universal scaling behavior in the vicinity of H(c1) and H(c2), indicating that the system is near a quantum critical point.
authors.affiliation: Department of Physics and The Center for Condensed Matter Sciences, University of Florida, P.O. Box 118440, Gainesville, Florida 32611-8440, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Watson
authors.forename: V N
authors.initials: VN
authors.lastname: Kotov
authors.forename: M W
authors.initials: MW
authors.lastname: Meisel
authors.forename: D W
authors.initials: DW
authors.lastname: Hall
authors.forename: G E
authors.initials: GE
authors.lastname: Granroth
authors.forename: W T
authors.initials: WT
authors.lastname: Montfrooij
authors.forename: S E
authors.initials: SE
authors.lastname: Nagler
authors.forename: D A
authors.initials: DA
authors.lastname: Jensen
authors.forename: R
authors.initials: R
authors.lastname: Backov
authors.forename: M A
authors.initials: MA
authors.lastname: Petruska
authors.forename: G E
authors.initials: GE
authors.lastname: Fanucci
authors.forename: D R
authors.initials: DR
authors.lastname: Talham