Pressure Study of Quantum Criticality in CeCoIn5

TL;DR

This study investigates the pressure and magnetic field effects on quantum criticality in CeCoIn5, revealing that the quantum critical point shifts inside the superconducting dome with pressure, supporting an antiferromagnetic quantum critical scenario.

Contribution

It provides experimental evidence that the quantum critical point in CeCoIn5 moves with pressure, challenging the idea that superconductivity causes non-Fermi liquid behavior.

Findings

Quantum critical point moves inside the superconducting dome with pressure.

Superconductivity is not directly responsible for non-Fermi liquid behavior.

Data supports an antiferromagnetic quantum critical point scenario.

Abstract

We report resistivity measurements in the normal state of CeCoIn5 down to 40 mK and simultaneously in magnetic fields up to 9 T in the [001] crystallographic direction and under pressures up to 1.3 GPa. At ambient pressure the data are consistent with a field tuned quantum critical point coincident with the superconducting upper critical field H_{c2}, as observed previously. We find that with increasing pressure the quantum critical point moves inside the superconducting dome to lower fields. Thus, we can rule out that superconductivity is directly responsible for the non-Fermi liquid behavior in CeCoIn5. Instead, the data point toward an antiferromagnetic quantum critical point scenario.