Non-centrosymmetric Superconductivity and Antiferromagnetic Order: Microscopic discussion of CePt$_3$Si

TL;DR

This paper investigates how antiferromagnetic order influences superconductivity in CePt$_3$Si, highlighting the role of spin fluctuations in stabilizing p-wave or d-wave pairing and analyzing phase diagrams under pressure.

Contribution

It provides a microscopic RPA analysis showing antiferromagnetic order's impact on pairing symmetry and gap structure in non-centrosymmetric heavy fermion superconductors.

Findings

Antiferromagnetic order affects low-energy physics and gap nodes.

Spin fluctuations induce p-wave or d-wave pairing.

Experimental data favor p-wave pairing in CePt$_3$Si.

Abstract

The influence of antiferromagnetic order on the superconductivity in the non-centrosymmetric heavy fermion compound CePt$_3$Si and related materials is discussed. Based on our RPA analysis for the extended Hubbard model two phases could be stabilized by a spin fluctuation induced pairing, with either dominantly p-wave or d-wave symmetry. The antiferromagnetic order plays an essential role for the low-energy physics, in particular, for the appearance of line nodes in the gap and the enhancement of spin susceptibility below $T_{\rm c}$. Various properties and possible phase diagrams under pressure are analyzed. The present experimental situation suggests that the p-wave phase is most likely realized in CePt$_3$Si.