Predicting New Heavy Fermion Materials within Carbon-Boron Clathrate Structures

TL;DR

This paper predicts new heavy fermion materials within carbon-boron clathrate structures using advanced theoretical methods, revealing potential for tunable strongly correlated electronic states like heavy electron behavior and Kondo insulating phases.

Contribution

It introduces rare earth carbon boron clathrates as a new platform for heavy fermion physics, combining density functional theory and dynamical mean field theory to predict their properties.

Findings

CeB$_3$C$_3$ shows increased density of states at Fermi level at low temperatures.

SmB$_3$C$_3$ potentially exhibits a Kondo insulating state.

Rare earth carbon boron clathrates are promising for novel strongly correlated materials.

Abstract

Heavy fermion materials have been a rich playground for strongly correlated physics for decades. However, engineering tunable and synthesizable heavy fermion materials remains a challenge. We strive to integrate heavy fermion properties into carbon boron clathrates as a universal structure which can host a diverse array of interesting physical phenomena. Using a combination of density functional theory and dynamical mean field theory, we study two rare earth carbon boron clathrates, SmB$_3$C$_3$ and CeB$_3$C$_3$, and explore properties arising from the strong electronic correlations. We find a significant increase in the density of states at the Fermi level in CeB$_3$C$_3$ as the temperature is lowered, indicating the development of a heavy electron state. In SmB$_3$C$_3$, a potential Kondo insulating state is identified. Both findings point to rare earth carbon boron clathrates as novel strongly correlated materials within a universally tunable structure, offering a fresh platform to innovate upon conventional heavy-fermion materials design.