The dynamics of azurite Cu$_3$(CO$_3$)$_2$(OH)$_2$ in a magnetic field as determined by neutron scattering

TL;DR

This study uses neutron scattering to explore azurite's complex magnetic behavior, revealing that simple 1D models are insufficient and that interchain interactions and anisotropic fields are essential for understanding its dynamics.

Contribution

The paper provides high-resolution neutron scattering data showing the inadequacy of the 1D Heisenberg model for azurite, highlighting the need for more complex interactions.

Findings

1D Heisenberg model is insufficient for azurite

Interchain interactions influence magnetic excitations

Anisotropic staggered fields are necessary for accurate modeling

Abstract

Azurite, a natural mineral made up of CuO chains, is also an intriguing spin-1/2 quantum magnet. There has been much debate as to the 1-dimensional (1D) nature of this material by theorists and experimentalists alike. The focus of this debate lies in the interactions between Cu-ions within the antiferromagnetically ordered state below 1.9 K. We present high-resolution inelastic neutron scattering data which highlight the complexity of the magnetic ground state of azurite. The application of magnetic fields and temperatures were used to probe the excitations revealing important information about the dynamics in this system. From this we are able to conclude that the 1D Heisenberg antiferromagnetic spin chain model is not sufficient to describe the dynamics in azurite. Instead additional coupling including interchain interactions and an anisotropic staggered field are necessary to fully model the observed excitations.