Quantum Heisenberg model on a sawtooth-chain lattice: Rotation-invariant Green's function method

TL;DR

This paper uses the rotation-invariant Green's function method to analyze the thermodynamic and dynamic properties of the spin-1/2 Heisenberg model on a sawtooth lattice, comparing results with exact methods and relating findings to mineral atacamite.

Contribution

It applies and validates the rotation-invariant Green's function method for a complex sawtooth lattice model, providing insights into its thermodynamic and dynamic behavior.

Findings

RGM predictions agree with exact diagonalization results

Thermodynamic properties are characterized for the sawtooth lattice

Dynamic properties are analyzed in relation to mineral atacamite

Abstract

We apply the rotation-invariant Green's function method (RGM) to study the spin $S=1/2$ Heisenberg model on a one-dimensional sawtooth lattice, which has two nonequivalent sites in the unit cell. We check the RGM predictions for observable quantities by comparison with the exact-diagonalization and finite-temperature-Lanczos calculations. We discuss the thermodynamic and dynamic properties of this model in relation to the mineral atacamite Cu$_2$Cl(OH)$_3$ complementing the RGM outcomes by results of other approaches.