YSix closely related YbT$_2$Zn$_{20}$ (T = Fe, Co, Ru, Rh, Os, Ir) heavy fermion compounds with large local moment degeneracy

TL;DR

This paper reports the discovery of six new Yb-based heavy fermion compounds, expanding the family of such materials and providing insights into how local moment degeneracy influences their thermodynamic and transport properties.

Contribution

It introduces six new YbT$_2$Zn$_{20}$ compounds, doubling the known Yb-based heavy fermion materials, and explores their properties related to local moment degeneracy.

Findings

Six new Yb-based heavy fermion compounds discovered

Systematic T variations minimally perturb Yb sites

Insights into degeneracy effects on thermodynamics and transport

Abstract

Heavy fermion compounds represent one of the most strongly correlated forms of electronic matter and give rise to low temperature states that range from small moment ordering to exotic superconductivity, both of which are often in close proximity to quantum critical points. These strong electronic correlations are associated with the transfer of entropy from the local moment degrees of freedom to the conduction electrons, and, as such, are intimately related to the low temperature degeneracy of the (originally) moment bearing ion. Here we report the discovery of six closely related Yb-based heavy fermion compounds, YbT$_2$Zn$_{20}$, that are members of the larger family of dilute rare earth bearing compounds: RT$_2$Zn$_{20}$ (T = Fe, Co, Ru, Rh, Os, Ir). This discovery doubles the total number of Yb-based heavy fermion materials. Given these compounds' dilute nature, systematic changes in T only weakly perturb the Yb site and allow for insight into the effects of degeneracy on the thermodynamic and transport properties of these model correlated electron systems.