Quasi-1D spin-1/2 Heisenberg magnets in their ordered phase: correlation functions

TL;DR

This paper investigates the ordered phase of weakly coupled antiferromagnetic spin-1/2 chains using an exact single-chain solution combined with RPA analysis, focusing on correlation functions relevant to materials like KCuF3 and CuGeO3.

Contribution

It introduces a method combining quantum Sine-Gordon model solutions with RPA to analyze interchain interactions in quasi-1D spin systems.

Findings

Calculated dynamical susceptibilities for different orders.

Provided insights into correlation functions in quasi-1D materials.

Applied the approach to real materials like KCuF3 and CuGeO3.

Abstract

We study weakly coupled antiferromagnetic spin chains in their ordered phase by combinining an exact solution of the single-chain problem with an RPA analysis of the interchain interaction. A single chain is described by a quantum Sine-Gordon model and dynamical staggered susceptibilities are determined by employing the formfactor approach to quantum correlation functions. We consider both antiferromagnetic order encountered in quasi-1D materials like $KCuF_3$ and spin-Peierls order as found in $CuGeO_3$.