Electron Correlation and Pairing States in Superconductors without Inversion Symmetry

TL;DR

This review explores how electron correlation influences unique superconducting properties in noncentrosymmetric heavy fermion systems, highlighting phenomena like mixed pairing states, magnetoelectric effects, and the specific case of CePt$_3$Si.

Contribution

It provides a comprehensive overview of the role of electron correlation in noncentrosymmetric superconductors, emphasizing heavy fermion systems and discussing possible pairing states in CePt$_3$Si.

Findings

Electron correlation enhances parity-violated superconducting features.

Unique properties include spin singlet-triplet mixing and magnetoelectric effects.

Heavy fermion superconductors without inversion symmetry exhibit prominent unconventional behaviors.

Abstract

This article is a pedagogical review of theoretical studies of noncentrosymmetric superconductors with particular emphasis on the role played by electron correlation, which is important for heavy fermion systems. We survey unique properties of parity-violated superconductivity such as the admixture of spin singlet and triplet states, unusual paramagnetism, large Pauli limiting fields, magnetoelectric effects, the helical vortex phase, and the anomalous Hall effect. It is pointed out that these remarkable features are strengthened by a strong electron correlation effect, and thus are prominent in heavy fermion superconductors without inversion symmetry. We also discuss possible pairing states realized in the heavy fermion system CePt$_3$Si.