Corrections to Pauling residual entropy and single tetrahedron based approximations for the pyrochlore lattice Ising antiferromagnet

TL;DR

This paper uses a Numerical Linked Cluster expansion to refine estimates of entropy, specific heat, and susceptibility in the pyrochlore lattice Ising antiferromagnet, improving upon single tetrahedron approximations.

Contribution

It provides higher-order corrections to single tetrahedron approximations using a 16th order NLC calculation, enhancing accuracy for thermodynamic properties.

Findings

Residual entropy corrected to 0.205507 from 0.20273

Corrections to single tetrahedron approximations are within a few percent

High temperature series expansion verifies calculation accuracy

Abstract

We study corrections to single tetrahedron based approximations for the entropy, specific heat and uniform susceptibility of the pyrochlore lattice Ising antiferromagnet, by a Numerical Linked Cluster (NLC) expansion. In a tetrahedron based NLC, the first order gives the Pauling residual entropy of ${1\over 2}\log{3\over 2}\approx 0.20273$. A 16-th order NLC calculation changes the residual entropy to 0.205507 a correction of 1.37 percent over the Pauling value. At high temperatures, the accuracy of the calculations is verified by a high temperature series expansion. We find the corrections to the single tetrahedron approximations to be at most a few percent for all the thermodynamic properties.