From magnetic and Kondo-compensated states to unconventional superconductivity in heavy fermions: a unified approach

TL;DR

This paper presents a unified microscopic approach to heavy fermion systems, revealing phase diagrams with quantum critical points and coexistence of antiferromagnetism and superconductivity, including unconventional pairing mechanisms.

Contribution

It introduces a comprehensive phase diagram for heavy fermions using a real space pairing approach within the Anderson-Kondo lattice model, highlighting the role of Kondo insulating states.

Findings

Identification of a quantum critical point where multiple phases meet

Kondo insulating state as the parent for superconductivity

Coexistence of antiferromagnetism and superconductivity with spin-triplet components

Abstract

Inspired by the recent experimental evidence of antiferromagnetism and superconductivity coexistence in heavy fermion CeRhIn$_5$, we propose a fully microscopic approach based on the idea of real space pairing within the Anderson-Kondo lattice model. We present an overall phase diagram incorporating the emergence of a quantum critical point, where Kondo insulating (KI), antiferromagnetic (AF) and superconducting (SC) phases meet. We also obtain the Kondo insulating state with totally compensated magnetic moments as the parental state for the emerging SC phases. Furthermore, the coexistent (AF+SC) phase may contain also a non-trivial spin-triplet gap component within the essentially spin-singlet pairing mechanism