Localized magnetic states in three dimensional Dirac solids

TL;DR

This paper demonstrates that strong spin-orbit interaction in 3D Dirac solids enables the formation of localized magnetic states with small Hubbard U, broadening the types of impurities that can host magnetism.

Contribution

It reveals that in 3D Dirac materials, localized magnetic states can form with small Hubbard U due to spin-orbit coupling, unlike traditional systems.

Findings

Magnetic states can form with small Hubbard U in 3D Dirac solids.

Strong spin-orbit interaction facilitates magnetic localization.

Potential for magnetic impurities with s or p orbitals.

Abstract

Formation of localized magnetic states in a metallic host is a classic problem ofcondensed matter physics formalized by P. W. Anderson within the so called single impurity Anderson model (SIAM). The general picture in a host of a simple one-band metal is that a large Hubbard $U$ in the impurity orbital is pre-requisite for the formation of localized magnetic states. In recent years three dimensional (3D) Dirac solids have emerged the hallmark of which is strong spin-orbit interaction. In this work we show that such a strong spin-orbit interaction allows to form localized magnetic states even with small values of Hubbard $U$. This opens up the fascinating possibility of forming magnetic states with $s$ or $p$ orbital impurities -- different from traditional paradigms of $d$ or $f$ orbital based magnetic moments.