Asymmetric melting of one-third plateau in kagome quantum antiferromagnets

TL;DR

This study reveals an asymmetric melting of the one-third magnetization plateau in kagome quantum antiferromagnets, driven by differences in low-energy state densities, with implications for experimental detection and understanding of the ice rule's role.

Contribution

It uncovers the asymmetric destruction of the magnetization plateau due to density of states differences, highlighting the role of the ice rule in kagome antiferromagnets.

Findings

Asymmetry in plateau melting observed upon heating.

Enhanced specific heat and entropy on the lower-field side.

Preservation of the ice rule influences the asymmetry.

Abstract

Asymmetric destruction of the one-third magnetization plateau upon heating is found in the spin-1/2 kagome Heisenberg antiferromagnets using the typical pure quantum state approach. The asymmetry originates from larger density of states of low-lying excited sates of $N_{\rm s}$ spin systems with magnetization $(1/3-2/N_{\rm s})$ than that of low-lying sates with magnetization $(1/3+2/N_{\rm s})$. The enhanced specific heat and entropy that reflect the larger density of states in the lower-field side of the plateau are detectable in candidate materials of the kagome antiferromagnets. We discuss that the asymmetry originates from the unprecedented preservation of the ice rule around the plateau.