Antiferromagnetism in doped anisotropic two-dimensional spin-Peierls systems

TL;DR

This paper investigates how impurity doping induces antiferromagnetic correlations in anisotropic 2D spin-Peierls systems, revealing the coexistence of antiferromagnetism and dimerization through numerical and mean-field analyses.

Contribution

It introduces a combined numerical and mean-field approach to study impurity effects and magnetic interactions in anisotropic 2D spin-Peierls systems, highlighting the sign-changing impurity coupling.

Findings

Impurity-induced antiferromagnetic correlations are demonstrated.

Magnetic coupling between impurities alternates with distance, reducing frustration.

Coexistence of antiferromagnetism and dimerization is supported by an effective model.

Abstract

We study the formation of antiferromagnetic correlations induced by impurity doping in anisotropic two-dimensional spin-Peierls systems. Using a mean-field approximation to deal with the inter-chain magnetic coupling, the intra-chain correlations are treated exactly by numerical techniques. The magnetic coupling between impurities is computed for both adiabatic and dynamical lattices and is shown to have an alternating sign as a function of the impurity-impurity distance, hence suppressing magnetic frustration. An effective model based on our numerical results supports the coexistence of antiferromagnetism and dimerization in this system.