Field dependence of the quantum ground state in the Shastry-Sutherland system SrCu2(BO3)2 F. Levy, I. Sheikin, C. Berthier, M. Horvatić, M. Takigawa, H. Kageyama, T. Waki and Y. Ueda EPL, 81 6 (2008) 67004 Published online: 29 February 2008 DOI: 10.1209/0295-5075/81/67004