Extension of structure integration to magnetic system

TL;DR

This paper extends the structure integration method to directly evaluate free energy in magnetic lattice systems, demonstrating efficiency and accuracy above critical temperature without iterative simulations.

Contribution

It introduces a lattice-dependent, parameter-independent DOS approach for magnetic systems, enabling direct free energy computation.

Findings

Efficient and accurate free energy evaluation above critical temperature

Elimination of iterative methods like Monte Carlo simulation

Applicable to large magnetic lattice systems

Abstract

We extend our previously developed method, "structure integration", to evaluate free energy directly for magnetic large systems on given lattice. The present method express the density of states(DOS) as the parameters independent of system but depend on lattice, and replace the DOS unknown a priori as that known a priori. Through two-dimensional square lattice Ising model, we find that the present method can evaluate magnetic free energy efficiently and accurately above critical temperature without iterative method like Monte Carlo simulation.