Antiferromagnetic quantum phase transition in superconducting phase in CeRhIn5

Abstract

We report on the pressure (P)-induced phase diagram of antiferromagnetism (AFM) and superconductivity (SC) which emerges at their boarder at zero magnetic field. The nuclear quadrupole resonance (NQR) measurements have revealed that AFM can take place in the superconducting state with Tc∼2.1K at P=2.05GPa and the AFM quantum phase transition (QPT) occurs near P=2.1GPa. These results suggest that AFM phase, AFM+SC uniformly coexisting phase, SC phase and paramagnetic phase all contact with each other at Ttetra∼2.1K and Ptetra∼2GPa which evidence the existence of the tetracritical point in the P–T phase diagram of AFM and SC in CeRnIn5.