Behavior of the Quantum Critical Point and the Fermi-liquid Domain in the Heavy Fermion Superconductor CeCoIn5 studied by resistivity

TL;DR

This study investigates the resistivity behavior of CeCoIn5 and its La-doped variants at very low temperatures under magnetic fields, revealing a Fermi liquid ground state and discussing the quantum critical point's location relative to the upper critical field.

Contribution

The paper provides detailed resistivity measurements in different crystallographic directions and magnetic fields, clarifying the nature of the quantum critical point in CeCoIn5.

Findings

Fermi liquid ground state observed above Hc2(0)

Resistivity follows  dependence at low temperatures

Discussion on the quantum critical point location

Abstract

We report detailed very low temperature resistivity measurements on the heavy fermion compounds Ce_{1-x}La_{x}CoIn5 (x=0 and x=0.01), with current applied in two crystallographic directions [100] (basal plane) and [001] (perpendicular to the basal plane) under magnetic field applied in the [001] or [011] direction. We found a Fermi liquid (\rho \propto T^{2}) ground state, in all cases, for fields above the superconducting upper critical field. We discuss the possible location of a field induced quantum critical point with respect to Hc2(0), and compare our measurements with the previous reports in order to give a clear picture of the experimental status on this long debated issue.