Ground State Phase Diagram of the Distorted S=1 Kagom\'e Heisenberg Antiferromagnets with Single-site Anisotropy

TL;DR

This study investigates the phase transitions in distorted S=1 kagome Heisenberg antiferromagnets with single-site anisotropy, revealing a transition analogous to the Haldane-large-D transition and presenting a comprehensive phase diagram.

Contribution

It provides the first detailed numerical analysis of the ground state phase diagram considering lattice distortion and anisotropy effects in S=1 kagome antiferromagnets.

Findings

Identification of a quantum phase transition similar to the Haldane-large-D transition.

The destruction of the hexagonal singlet solid ground state under strong anisotropy.

Construction of a ground state phase diagram incorporating lattice distortion and anisotropy.

Abstract

The ground state phase transitions in the distorted S=1 kagome Heisenberg antiferromagnet (KHAF) with single-site anisotropy D are studied by the numerical exact diagonalization method. For strong easy plane anisotropy, the hexgonal singlet solid (HSS) ground state of the uniform KHAF is destroyed and large-D state is realized. The quantum phase transition between these two states is analogous to the Haldane-large-D transition in the S=1 antiferromagnetic Heisenberg chain. The combined effect of the sqrt(3) times sqrt(3) lattice distortion and single site anisotropy is also investigated. The ground state phase diagram expected from the numerical results is presented. The presence of this transition is consistent with the HSS picture of the ground state of the uniform S=1 KHAF and supports its validity.