Multipole Fluctuations in Filled Skutterudites

TL;DR

This study investigates multipole susceptibilities in filled skutterudites across different electron counts, revealing diverse fluctuation dominance and potential material relevance.

Contribution

It provides a detailed analysis of multipole fluctuations in filled skutterudites using a multiorbital Anderson model with the $j$-$j$ coupling scheme, highlighting the role of electron number.

Findings

Magnetic fluctuations dominate at n=1.

Both magnetic and quadrupole fluctuations are significant at n=2 and 4.

Octupole fluctuations are important at n=3 and 5.

Abstract

In order to clarify exotic multipole properties of filled skutterudites, we evaluate multipole susceptibility for $n$=1$\sim$5, where $n$ is the local $f$-electron number, on the basis of a multiorbital Anderson model constructed using the $j$-$j$ coupling scheme. For $n$=1, magnetic fluctuations dominate over low-temperature electronic properties, while for $n$=2 and 4, electronic states are dominated by both magnetic and quadrupole fluctuations. For $n$=3 and 5, octupole fluctuations are found to be significant, depending on the crystalline electric field potential. We discuss possible relevance of the results to actual materials.