Spin stiffness in the frustrated Heisenberg antiferromagnet

TL;DR

This paper calculates the spin stiffness of the S=1/2 frustrated Heisenberg antiferromagnet using Schwinger boson mean-field theory, considering both Néel and collinear phases, and analyzes finite-size scaling behavior.

Contribution

It introduces a direct calculation method for spin stiffness in frustrated systems, including anisotropy effects and finite-size scaling analysis.

Findings

Scaling exponents match unfrustrated case

Finite-size effects are systematically analyzed

Both Néel and collinear orderings are considered

Abstract

We calculate the spin stiffness of the S=1/2 frustrated Heisenberg antiferromagnet directly from a general formula which is evaluated in the Schwinger boson mean-field approximation. Both N\'eel and collinear ordering are considered. For collinear ordering, we take the anisotropy of this phase into account, unlike previous approaches. For N\'eel ordering, a detailed study is made of the finite-size scaling behavior of the two terms that make up the spin stiffness. The exponents of the scaling with the system size of the two terms comprising the spin stiffness turn out to be identical to those of the unfrustrated case.