Impurity-induced magnetic order in low dimensional spin gapped materials

TL;DR

This study investigates how non-magnetic impurities induce magnetic order in low-dimensional spin-gapped materials, revealing a universal freezing process of impurity-induced moments across different compounds.

Contribution

It provides a unified explanation for impurity-induced magnetic freezing in various low-dimensional spin-gapped systems using experimental and simulation data.

Findings

Impurities induce antiferromagnetic polarizations extending over several unit cells.

At low temperatures, these polarizations freeze in a universal manner.

The results suggest a common framework for impurity effects in spin-gapped materials.

Abstract

We have studied the effect of non-magnetic Zn impurities in the coupled spin-ladder Bi(Cu1xZnx)2PO6 using 31P NMR, muSR and Quantum Monte Carlo simulations. Our results show that the impurities induce in their vicinity antiferromagnetic polarizations, extending over a few unit cells. At low temperature, these extended moments freeze in a process which is found universal among various other spin-gapped compounds: isolated ladders, Haldane or Spin-Peierls chains. This allows us to propose a simple common framework to explain the generic low-temperature impurity induced freezings observed in low dimensional spin-gapped materials.