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 plateaux 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 intra-dimer exchange interactions J'/J=0.63. It is further predicted that the intermediate phase between the 1/3 and 1/2 plateau 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.
@article{arxiv.1308.4151,
title = {Magnetization of SrCu2(BO3)2 in ultrahigh magnetic fields up to 118 T},
author = {Y. H. Matsuda and N. Abe and S. Takeyama and H. Kageyama and P. Corboz and A. Honecker and S. R. Manmana and G. R. Foltin and K. P. Schmidt and F. Mila},
journal= {arXiv preprint arXiv:1308.4151},
year = {2013}
}