Multipole State of Heavy Lanthanide Filled Skutterudites

TL;DR

This paper investigates the complex multipole properties of heavy lanthanide-filled skutterudites using a microscopic seven-orbital Anderson model, revealing diverse multipole behaviors across different elements.

Contribution

It provides a detailed microscopic analysis of multipole moments in heavy lanthanide skutterudites, highlighting unexpected and exotic multipole states for various elements.

Findings

Gd shows coexistence of quadrupole and dipole moments.

Ho exhibits an exotic octupole-dominated state.

Dy, Er, Yb have dominant dipole and higher multipole moments.

Abstract

We discuss multipole properties of filled skutterudites containing heavy lanthanide Ln from a microscopic viewpoint on the basis of a seven-orbital Anderson model. For Ln=Gd, in contrast to naive expectation, quadrupole moments remain in addition to main dipole ones. For Ln=Ho, we find an exotic state governed by octupole moment. For Ln=Tb and Tm, no significant multipole moments appear at low temperatures, while for Ln=Dy, Er, and Yb, dipole and higher-order multipoles are dominant. We briefly discuss possible relevance of these multipole states with actual materials.