Generation of localized magnetic moments in the charge-density-wave state

TL;DR

This paper introduces a model explaining how localized magnetic moments can form in charge-density-wave materials, aligning with experimental observations in specific compounds.

Contribution

It presents a new theoretical mechanism for magnetic moment formation in charge-density-wave systems using an Anderson impurity model.

Findings

Magnetic susceptibility diverges at low temperatures.

Heat capacity shows a low-field peak.

Model aligns with experimental data on TaS3 and blue bronze.

Abstract

We propose a mechanism explaining the generation of localized magnetic moments in charge-density-wave compounds. Our model Hamiltonian describes an Anderson impurity placed in a host material exhibiting the charge-density wave. There is a region of the model's parameter space, where even weak Coulomb repulsion on the impurity site is able to localize the magnetic moment on the impurity. The phase diagram of a single impurity at T=0 is mapped. To establish the connection with experiment thermodynamic properties of a random impurity ensemble is studied. Magnetic susceptibility of the ensemble diverges at low temperature; heat capacity as a function of the magnetic field demonstrates pronounced low field peak. Both features are consistent with experiments on orthorhombic TaS3 and blue bronze.