Magnetization plateaux in the classical Shastry-Sutherland lattice

TL;DR

This study explores how thermal fluctuations influence magnetization plateaux in the classical Shastry-Sutherland lattice, revealing entropic effects that stabilize specific spin states and mapping their phase diagram.

Contribution

It provides a detailed analysis of thermal effects on magnetization plateaux in the classical Shastry-Sutherland lattice, combining spin wave theory and Monte Carlo simulations.

Findings

Observation of magnetization quasi-plateaux at 1/3 saturation magnetization

Identification of entropic selection as the mechanism stabilizing specific states

Phase diagram illustrating spin configuration domains in magnetic field-temperature space

Abstract

We investigated the classical Shastry-Sutherland lattice under an external magnetic field in order to understand the recently discovered magnetization plateaux in the rare-earth tetraborides compounds RB$_4$. A detailed study of the role of thermal fluctuations was carried out by mean of classical spin waves theory and Monte-Carlo simulations. Magnetization quasi-plateaux were observed at 1/3 of the saturation magnetization at non zero temperature. We showed that the existence of these quasi-plateaux is due to an entropic selection of a particular collinear state. We also obtained a phase diagram that shows the domains of existence of different spin configurations in the magnetic field versus temperature plane.