Spin-Liquid State for Two-Dimensional Heisenberg Antiferromagnets on a Triangular Lattice

TL;DR

This paper investigates the spin-liquid state in a two-dimensional triangular lattice antiferromagnetic Heisenberg model using a Green's function approach, revealing gapless excitations and a ground-state energy consistent with variational Monte Carlo results.

Contribution

It introduces a self-consistent Green's function method to study the spin-liquid state, providing new insights into its excitation spectra and thermodynamic properties.

Findings

Spin excitation spectra are gapless.

Ground-state energy per site is -0.966J.

Results agree with variational Monte Carlo calculations.

Abstract

The spin liquid state of the antiferromagnetic Heisenberg model on a triangular lattice is studied within the self-consistent Green's function method. It is shown that the spin excitation spectra is gapless, and ground-state energy per site is $E_{g}/NJ=-0.966$, which is in very good agreement with the results obtained within the variational Monte Carlo method based on the resonating-valence-bond state. Some thermodynamic properties are also discussed.