Coexistence of SDW, d-wave singlet and staggered $\pi$-triplet superconductivity

TL;DR

This paper investigates the coexistence and competition of various superconducting and magnetic states in correlated materials, revealing novel phase transitions influenced by magnetic fields and particle-hole asymmetry, with potential explanations for experimental puzzles.

Contribution

It provides a detailed mean-field analysis of how staggered triplet superconductivity coexists with d-wave singlet superconductivity and SDW, especially under magnetic fields, highlighting new phase transition phenomena.

Findings

Particle-hole asymmetry enables coexistence of states.

Magnetic fields induce transitions similar to Fulde-Ferrel phases.

Transitions include coexistence of multiple orders in high fields.

Abstract

We have studied the competition and coexistence of staggered triplet SC with d-wave singlet SC and SDW in the mean-field approximation. Detailed numerical studies demonstrate that particle-hole asymmetry mixes these states and therefore they are simultaneously present. Even more interesting were the results of our study of the influence of a uniform magnetic field. We observe novel transitions that show the characteristics of Fulde-Ferrel phases, yet they concern transitions to different combinations of the above orders. For example, above a given field, in a particle-hole symmetric system we observe a transition from d-wave singlet SC to a state in which d-wave singlet SC coexists with staggered triplet SC and SDW. We believe our results may provide, among others, a direct explanation to recent puzzles about the Fulde Ferrel like states that are apparently observed in CeCoIn5.