Magnetic nanopantograph in the SrCu 2 (BO 3 ) 2 Shastry–Sutherland lattice

Significance The spins of the unpaired electrons in a solid tend to align along an applied magnetic field. In the case of antiferromagnetic materials having competing interactions (frustration) it is common to observe that the magnetization increases, exhibiting complicated structures with discrete jumps and plateaus. SrCu 2 (BO 3 ) 2 is one of these materials, for which we find experimentally that its macroscopic physical dimensions also change with the magnetic field, mimicking the behavior in the magnetization. Using quantum mechanics, we show quantitatively that due to the orthogonal arrangement of the magnetic Cu 2+ dimers acting as pantographs, minute deformations allow significant reduction in the effective interactions responsible for the antiferromagnetism. This drop is sufficient to compensate the elastic energy loss in the lattice deformation.

Magnetic nanopantograph in the SrCu ₂ (BO ₃ ) ₂ Shastry–Sutherland lattice Journal Articles