Half-magnetization plateau stabilized by structural distortion in the antiferromagnetic Heisenberg model on a pyrochlore lattice

TL;DR

This paper explains how a strong half-magnetization plateau in pyrochlore antiferromagnets is stabilized by spin-lattice coupling, with implications for specific spinel oxides, advancing understanding of frustrated magnetic systems.

Contribution

It introduces a detailed symmetry analysis showing how spin-lattice interactions stabilize the half-magnetization plateau in pyrochlore antiferromagnets.

Findings

Half-magnetization plateau is stabilized by spin-lattice coupling.

The theory explains experimental observations in CdCr2O4 and HgCr2O4.

Symmetry analysis clarifies the plateau's robustness.

Abstract

Magnetization plateaus, visible as anomalies in magnetic susceptibility at low temperatures, are one of the hallmarks of frustrated magnetism. We show how an extremely robust half-magnetization plateau can arise from coupling between spin and lattice degrees of freedom in a pyrochlore antiferromagnet, and develop a detailed symmetry of analysis of the simplest possible scenario for such a plateau state. The application of this theory to the spinel oxides CdCr2O4 and HgCr2O4, where a robust half magnetization plateau has been observed, is discussed.