Coexistence of Superconductivity and Antiferromagnetism Probed by Simultaneous NMR and Electrical Transport in (TMTSF)2PF6

TL;DR

This study investigates the coexistence of superconductivity and antiferromagnetism in (TMTSF)2PF6 through simultaneous NMR and electrical transport experiments, revealing a tricritical point and phase coexistence with hysteresis near the phase boundary.

Contribution

It provides the first direct experimental evidence of phase coexistence and hysteresis between antiferromagnetic and superconducting states in (TMTSF)2PF6 using combined NMR and transport measurements.

Findings

Identification of a tricritical point separating different phase transition regimes.

Evidence of macroscopic coexistence of SDW and superconducting phases.

Observation of hysteretic effects indicating phase coexistence with little mutual interaction.

Abstract

We report simultaneous NMR and electrical transport experiments in the pressure range near the boundary of the antiferromagnetic spin density wave (SDW) insulator and the metal-lic/superconducting (SC) phase in (TMTSF)2PF6. Measurements indicate a tricritical point separat-ing a line of second order SDW/metal transitions from a line of first order SDW/metal(SC) transi-tions with coexistence of macroscopic regions of SDW and metal(SC) order, with little mutual in-teraction but strong hysteretic effects. NMR results quantify the fraction of each phase.