Equilibrium current vortices in rare-earth-doped simple metals

TL;DR

This paper models how dilute rare-earth impurities in simple metals generate equilibrium current vortices due to spin-orbit coupling, affecting observable magnetic fields and shifts.

Contribution

It introduces a theoretical model for equilibrium current vortices around rare-earth impurities in light metals, highlighting the role of spin-orbit coupling in these phenomena.

Findings

Current vortices are induced by open 4f subshells and spin-orbit coupling.

The current oscillates similarly to RKKY spin polarization.

Observable effects include Oersted fields and Knight shifts.

Abstract

Dilute alloys of rare earths have played a vital role in understanding magnetic phenomena. Here, we model the ground state of dilute 4f rare-earth impurities in light metals. When the 4f subshells are open (but not half-filled), the spin-orbit coupling imprints a rotational charge current of conduction electrons around rare-earth atoms. The sign and amplitude of the current oscillate similar to the RKKY spin polarization. We compute the observable effect, namely the Oersted field generated by the current vortices and the Knight shift.