Nature of superconducting state in the new phase in (TMTSF)$_{2}$PF$_{6}$ under pressure

TL;DR

This paper investigates a newly observed phase in (TMTSF)$_{2}$PF$_{6}$ under pressure, revealing that the coexistence of superconductivity and spin-density wave involves a triplet pairing state.

Contribution

It proposes that the intermediate phase where SC coexists with SDW features a triplet pairing state, advancing understanding of unconventional superconductivity in organic materials.

Findings

Superconductivity coexists with SDW below a critical pressure.

The new phase involves a triplet pairing state.

Coexistence occurs on a microscopic scale.

Abstract

The unusual phase has been recently observed in the organic material (TMTSF)$_{2}$PF$_{6}$, where superconductivity (SC) coexists with spin-density wave (SDW) in the pressure interval $p_{c1}<p<p_{c}$ below the first order transition into SC or normal metal phase. Assuming that the coexistence takes place on the microscopic scale, we consider the properties of the intermediate phase. We show that the new superconducting state inside SDW phase just above $p_{c1}$ must bear a triplet pairing.