Coexistence of CDW with staggered superconductivity in a ferromagnetic material

TL;DR

This paper explores the coexistence of charge density waves and a novel form of staggered superconductivity with finite momentum in ferromagnetic materials, revealing new states and phase transitions.

Contribution

It demonstrates for the first time how particle-hole asymmetry enables coexistence of CDW and staggered SC, and links these phenomena to experimental observations in UGe₂.

Findings

Coexistence of CDW and staggered SC in ferromagnetic media.

Identification of SC domes near CDW collapse.

Transitions resembling pressure phase diagrams in UGe₂.

Abstract

In usual superconductivity (SC), the pairs have zero total momentum irrespective of their symmetry. Staggered SC would involve, instead, pairs with a finite commensurate total momentum, but such exotic states have never been proven to be realized in nature. Here we study for the first time the influence of particle-hole asymmetry on the competition of staggered SC with Charge Density Waves (CDW) in a ferromagnetic medium. We obtain unprecedented situations in which CDW and staggered SC coexist. We also obtain cases of a SC dome near the collapse of a CDW state as well as cascades of transitions that exhibit remarkable similarities with the pressure phase diagram in UGe$_2$ suggesting that SC in this material may be staggered coexisting and competing with a CDW state.