Local physics of magnetization plateaux in the Shastry-Sutherland model.

We address the physical mechanism responsible for the emergence of magnetization plateaux in the Shastry-Sutherland model. By using a hierarchical mean-field approach, we demonstrate that a plateau is stabilized in a certain spin pattern, satisfying local commensurability conditions derived from our formalism. Our results provide evidence in favor of a robust local physics nature of the plateaux states and are in agreement with recent NMR experiments on SrCu2(BO3)2.