Magnetization plateaus and sublattice ordering in easy axis Kagome lattice antiferromagnets

TL;DR

This paper investigates easy axis kagome antiferromagnets with dominant single-ion anisotropy, revealing a one-third magnetization plateau and a nematic sublattice order that may cause glassy dynamics.

Contribution

It demonstrates the existence of a magnetization plateau and nematic order in kagome antiferromagnets with strong anisotropy, highlighting new quantum fluctuation effects.

Findings

Presence of a one-third magnetization plateau over a broad field range

Development of nematic order breaking sublattice rotation symmetry

Potential for glassy freezing due to slow dynamics

Abstract

We study kagome lattice antiferromagnets where the effects of easy axis single-ion anisotropy ($D$) dominates over the Heisenberg exchange $J$. For $S \ge 3/2$, virtual quantum fluctuations help lift the extensive classical degeneracy. We demonstrate the presence of a one-third magnetization plateau for a broad range of magnetic fields $J^3/D^2 \lesssim B \lesssim JS$ along the easy axis. The fully equilibriated system at low temperature on this plateau develops an unusual {\em nematic} order that breaks sublattice rotation symmetry but not translation symmetry--however, extremely slow dynamics associated with this ordering is expected to lead to glassy freezing of the system on intermediate time-scales.