title: Anisotropic cascade of field-induced phase transitions in the frustrated spin-ladder system BiCu2PO6.
abstract: BiCu(2)PO(6) is a frustrated two-leg spin-ladder compound with a spin gap that can be closed with a magnetic field of approximately 20 T. This quantum phase transition and its related phase diagram as a function of magnetic field and temperature (H, T) are investigated up to 60 T by means of specific heat, magnetocaloric effect, magnetization, and magnetostriction measurements. In contrast to other gapped quantum magnets, BiCu(2)PO(6) undergoes a series of unexpected first- and second-order phase transitions when an external magnetic field is applied along the crystallographic c axis. The application of a magnetic field along the b axis induces two second-order phase transitions. We propose that the anisotropy and complex phase diagram result from the interplay between strong geometrical frustration and spin-orbit interaction necessary for the description of this fascinating magnetic system.
authors.affiliation: MPA-CMMS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Kohama
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Atsuko
authors.initials: A
authors.lastname: Uchida
authors.forename: Krunoslav
authors.initials: K
authors.lastname: Prsa
authors.forename: Sergei
authors.initials: S
authors.lastname: Zvyagin
authors.forename: Yuri
authors.initials: Y
authors.lastname: Skourski
authors.forename: Ross D
authors.initials: RD
authors.lastname: McDonald
authors.forename: Luis
authors.initials: L
authors.lastname: Balicas
authors.forename: Henrik M
authors.initials: HM
authors.lastname: Ronnow
authors.forename: Christian
authors.initials: C
authors.lastname: Rüegg
authors.forename: Marcelo
authors.initials: M
authors.lastname: Jaime