Quantum criticality in layered CeRhIn_{5-x}Sn_x compared with cubic CeIn$_{3-x}Sn_x

TL;DR

This study compares quantum critical behavior in layered CeRhIn_{5-x}Sn_x and cubic CeIn_{3-x}Sn_x, revealing that a 3D itinerant model explains criticality in both despite structural differences, likely due to weak disorder effects.

Contribution

It demonstrates that crystalline anisotropy is unimportant for quantum criticality in these doped heavy fermion systems, supporting a universal 3D itinerant model.

Findings

Both systems exhibit a quantum critical point with a divergent Grüneisen ratio.

The 3D itinerant model explains quantum criticality in both layered and cubic systems.

Crystalline anisotropy is negligible due to weak disorder effects.

Abstract

We report low-temperature thermal-expansion measurements on single crystals of the {\it layered} heavy fermion system \cri ($0.3\leq x \leq 0.6$) and compare it with a previous study on the related {\it cubic} system \ci [R. K\"{u}chler {\it et al.}, Phys. Rev. Lett. {\bf 96}, 256403 (2006)]. Both systems display a quantum critical point as proven by a divergent Gr\"uneisen ratio. Most remarkably, the three-dimensional itinerant model explains quantum criticality in {\it both} systems, suggesting that the crystalline anisotropy in \cri is unimportant. This is ascribed to the effect of weak disorder in these doped systems.