title: Magnetization of SrCu2(BO3)2 in ultrahigh magnetic fields up to 118 T.
abstract: The magnetization process of the orthogonal-dimer antiferromagnet SrCu2(BO3)2 is investigated in high magnetic fields of up to 118 T. A 1/2 plateau is clearly observed in the field range 84 to 108 T in addition to 1/8, 1/4, and 1/3 plateaus at lower fields. Using a combination of state-of-the-art numerical simulations, the main features of the high-field magnetization, a 1/2 plateau of width 24 T, a 1/3 plateau of width 34 T, and no 2/5 plateau, are shown to agree quantitatively with the Shastry-Sutherland model if the ratio of inter- to intradimer exchange interactions J'/J=0.63. It is further predicted that the intermediate phase between the 1/3 and 1/2 plateaus is not uniform but consists of a 1/3 supersolid followed by a 2/5 supersolid and possibly a domain-wall phase, with a reentrance into the 1/3 supersolid above the 1/2 plateau.
authors.affiliation: Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Y H
authors.initials: YH
authors.lastname: Matsuda
authors.forename: N
authors.initials: N
authors.lastname: Abe
authors.forename: S
authors.initials: S
authors.lastname: Takeyama
authors.forename: H
authors.initials: H
authors.lastname: Kageyama
authors.forename: P
authors.initials: P
authors.lastname: Corboz
authors.forename: A
authors.initials: A
authors.lastname: Honecker
authors.forename: S R
authors.initials: SR
authors.lastname: Manmana
authors.forename: G R
authors.initials: GR
authors.lastname: Foltin
authors.forename: K P
authors.initials: KP
authors.lastname: Schmidt
authors.forename: F
authors.initials: F
authors.lastname: Mila