New Superconducting and Magnetic Phases Emerge on the Magnetic Criticality in CeIn₃

Abstract

We report the discovery of new superconducting and novel magnetic phases in\nCeIn$_3$ on the verge of antiferromagnetism (AFM) under pressure ($P$) through\nthe In-nuclear quadrupole resonance (NQR) measurements. We have found a\n$P$-induced phase separation of AFM and paramagnetism (PM) without any trace\nfor a quantum phase transition in CeIn$_3$. A new type of superconductivity\n(SC) was found in $P=2.28-2.5$ GPa to coexist with AFM that is magnetically\nseparated from PM where the heavy fermion SC takes place. We propose that the\nmagnetic excitations such as spin-density fluctuations induced by the\nfirst-order magnetic phase transition might mediate attractive interaction to\nform Cooper pairs.\n