Direct calculation of the spin stiffness on square, triangular and cubic lattices using the coupled cluster method

TL;DR

This paper introduces a coupled cluster method to directly compute the spin stiffness in quantum antiferromagnets on various lattices, achieving highly accurate results that surpass previous methods.

Contribution

The paper develops a novel coupled cluster approach for direct spin stiffness calculation, providing more precise results especially for the triangular lattice.

Findings

Results agree with best literature values for square and cubic lattices.

Achieves unprecedented precision for the triangular lattice.

Demonstrates the effectiveness of the coupled cluster method for spin property calculations.

Abstract

We present a method for the direct calculation of the spin stiffness by means of the coupled cluster method. For the spin-half Heisenberg antiferromagnet on the square, the triangular and the cubic lattices we calculate the stiffness in high orders of approximation. For the square and the cubic lattices our results are in very good agreement with the best results available in the literature. For the triangular lattice our result is more precise than any other result obtained so far by other approximate method.