Magnetic and superconducting instabilities in the periodic Anderson model: an RPA stud

TL;DR

This paper investigates magnetic and superconducting phase instabilities in the periodic Anderson model using RPA, revealing how critical temperatures vary with electronic density and hybridization, and aligning with experimental heavy-fermion behaviors.

Contribution

It provides a theoretical analysis of magnetic and superconducting transitions in the periodic Anderson model considering infinite Coulomb repulsion, using RPA to connect with experimental observations.

Findings

Critical temperature T_c is much smaller than Neel temperature near magnetic order.

Magnetic and superconducting behaviors originate from fluctuating boson fields.

Results qualitatively agree with heavy-fermion material data.

Abstract

We study the magnetic and superconducting instabilities of the periodic Anderson model with infinite Coulomb repulsion U in the random phase approximation. The Neel temperature and the superconducting critical temperature are obtained as functions of electronic density (chemical pressure) and hybridization V (pressure). It is found that close to the region where the system exhibits magnetic order the critical temperature T_c is much smaller than the Neel temperature, in qualitative agreement with some T_N/T_c ratios found for some heavy-fermion materials. In our study, all the magnetic and superconducting physical behaviour of the system has its origin in the fluctuating boson fields implementing the infinite on-site Coulomb repulsion among the f-electrons.