Exact diagonalization study of the spin-1 two-dimensional $J_1$-$J_3$ Heisenberg model on a triangular lattice

TL;DR

This study uses exact diagonalization to analyze the spin-1 Heisenberg model on a triangular lattice, revealing insights into its ground and excited states relevant for understanding NiGa$_2$S$_4$.

Contribution

It provides detailed energy spectra and correlation functions for the model using exact diagonalization, complementing previous methods.

Findings

Qualitative agreement with earlier results

Ground and excited state energies characterized

Spin-spin correlations analyzed

Abstract

The spin-1 Heisenberg model on a triangular lattice with the ferromagnetic nearest- and antiferromagnetic third-nearest-neighbor exchange interactions, $J_1=-(1-p)J$ and $J_2=pJ$, $J>0$ $ (0 \leq p \leq 1)$, is studied with the use of the SPINPACK code. This model is applicable for the description of the magnetic properties of NiGa$_2$S$_4$. The ground, low-lying excited state energies and spin-spin correlation functions have been found for lattices with N=16 and N=20 sites with the periodic boundary conditions. These results are in qualitative agreement with earlier authors' results obtained with Mori's projection operator technique.