Spin glass properties of an Ising antiferromagnet on the Archimedean (3,12^2) lattice

TL;DR

This paper explores the magnetic properties of an Ising antiferromagnet on the Archimedean (3,12^2) lattice, revealing degenerate ground states, temperature-dependent maxima in specific heat and susceptibility, and complex magnetization behavior due to metastability.

Contribution

It provides the first detailed numerical analysis of the magnetic behavior of an Ising antiferromagnet on the (3,12^2) lattice, highlighting ground state degeneracy and metastable effects.

Findings

Maxima in specific heat and susceptibility at T>0

Presence of degenerate ground states with translational invariance

Erratic magnetization curves due to metastable states

Abstract

We investigate magnetic properties of a two-dimensional periodic structure with Ising spins and antiferromagnetic nearest neighbor interaction. The structure is topologically equivalent to the Archimedean (3,12^2) lattice. The ground state energy is degenerate. In some ground states, the spin structure is translationally invariant, with the same configuration in each unit cell. Numerical results are reported on specific heat and static magnetic usceptibility against temperature. Both quantities show maxima at temperature T>0. They reveal some sensitivity on the initial state in temperatures where the Edwards--Anderson order parameter is positive. For zero temperature and low frequency of the applied field, the magnetic losses are negligible. However, the magnetization curve displays some erratic behavior due to the metastable states.