Magnetic properties of the quantum Shastry–Sutherland model with spin S = 1/2

Abstract

Magnetization dependence on the external magnetic field was studied in a system with the Shastry–Sutherland lattice using exact diagonalization method at zero temperature within the xxz-model with spin S = 1/2. It was found that contrary to the classical Heisenberg model, the magnetization plateaus corresponding to m* = m/msat = 1/4, 1/3, and 1/2 (here msat is the saturation magnetization) exist even in the case of isotropic exchange interactions. The effect of exchange interaction on the width of the plateaus was studied. It was shown that depending on the ratio of exchange constants, there exist three regions corresponding to different types of the behavior of the system: the regions of a Neel-like antiferromagnet, a “dimer” antiferromagnet, and an intermediate region where the unique properties of Shastry–Sutherland lattices are most pronounced. The boundaries of these regions were also determined.

Magnetic Properties of Quasi-One-Dimensional Crystals Formed by Graphene Nanoclusters and Embedded Atoms of the Transition Metals

“…Within this approach, the gap is derived by numerically estimating the width of zero magnetization plateau then extrapolated to zero external magnetic field. The field dependencies of the magnetization at zero and low temperatures were very informative of characteristics of energy spectra structure [41]. This is why we paid special attention to studying these dependencies of the nanoribbons.…”