# Realization of Kondo chain in CeCo$_2$Ga$_8$

## TL;DR

This study demonstrates that CeCo$_2$Ga$_8$ is a quasi-one-dimensional heavy-fermion material exhibiting Kondo coherence primarily along its c-axis, providing a concrete example of a Kondo chain with significant magnetic anisotropy.

## Contribution

The paper provides experimental evidence that CeCo$_2$Ga$_8$ is a Kondo chain with strong magnetic anisotropy, highlighting its quasi-one-dimensional heavy-fermion behavior.

## Key findings

- Resistivity shows Kondo coherence below 17 K along c-axis.
- Magnetic anisotropy ratio of exchange interactions is 4-5.
- CeCo$_2$Ga$_8$ is a quasi-one-dimensional heavy-fermion compound.

## Abstract

We revisited the anisotropy of the heavy-fermion material CeCo$_2$Ga$_8$ by measuring the electrical resistivity and magnetic susceptibility along all the principal $\mathbf{a}$-, $\mathbf{b}$- and $\mathbf{c}$-axes. Resistivity along $\mathbf{c}$-axis ($\rho_c$) shows clear Kondo coherence below about 17 K, while both $\rho_{a}$ and $\rho_{b}$ remain incoherent down to 2 K. The magnetic anisotropy is well understood within the theoretical frame of crystalline electric field effect in combination with magnetic exchange interactions. We found the anisotropy ratio of these magnetic exchange interactions, $|J_{ex}^c/J_{ex}^{a,b}|$, reaches a large value of 4-5. We, therefore, firmly demonstrate that CeCo$_2$Ga$_8$ is a quasi-one-dimensional heavy-fermion compound both electrically and magnetically, and thus provide a realistic example of \textit{Kondo chain}.