We show that the critical fields of the magnetization plateaus of the Shastry-Sutherland model decrease significantly upon increasing the ratio of inter- to intra-dimer coupling, and accordingly that the magnetization plateaus of SrCu_2(BO_3)_2 shift to lower field under pressure, making the first two plateaus at 1/8 and 2/15 potentially accessible to neutron scattering experiments. These conclusions are based on the derivation of an effective classical model of interacting pinwheel-shaped spin-2 bound states using a combination of perturbative and graph-based continuous unitary transformations, showing that pinwheel crystals are indeed the lowest-energy plateau structures at low magnetization, and that a simple model of intermediate-range two-body repulsion between pinwheels is able to account quantitatively for the plateau sequence.
@article{arxiv.1601.00793,
title = {Pressure dependence of the magnetization plateaus of SrCu_2(BO_3)_2},
author = {D. A. Schneider and K. Coester and F. Mila and K. P. Schmidt},
journal= {arXiv preprint arXiv:1601.00793},
year = {2016}
}