Translational Symmetry Broken Magnetization Plateau of the $S=2$ Antiferromagnetic Chain with Anisotropies

TL;DR

This study explores the phase diagram of an $S=2$ antiferromagnetic chain with anisotropies, revealing a new magnetization plateau phase with broken translational symmetry through numerical analysis.

Contribution

It extends previous phase diagrams by identifying a novel half-magnetization plateau phase with broken translational symmetry in the $S=2$ chain.

Findings

Identified a new magnetization plateau phase with broken translational symmetry.

Extended the phase diagram to include wider anisotropy regions.

Confirmed the existence of multiple plateau phases due to different mechanisms.

Abstract

The magnetization plateau of the $S=2$ antiferromagnetic chain with interaction and single-ion anisotropies is investigated using the numerical diagonalization of finite-size clusters and some size scaling analyses. The previous level spectroscopy analysis indicated that two different magnetization plateau phases appear at half of the saturation magnetization. One is due to the large-$D$ mechanism and the other is due to the Haldane one. In the present study the phase diagram is extended to wider region of the anisotropies. As a result we find another half magnetization plateau phase, where the translational symmetry is spontaneously broken .