Spontaneous formation of a superconducting and antiferromagnetic hybrid state in SrFe2As2 under high pressure

TL;DR

This study uncovers a spontaneous nano-scale hybrid state of superconductivity and antiferromagnetism in SrFe2As2 under high pressure, demonstrating self-organization of these phases in a clean system.

Contribution

It reveals the formation of a spontaneous superconducting and antiferromagnetic hybrid state in SrFe2As2 under high pressure, a novel self-organized heterostructure.

Findings

Simultaneous development of SC and AF orders below 30 K at 5.4 GPa

Presence of residual density of states indicating proximity effects

Observation of a nano-scale hybrid structure of SC and AF phases

Abstract

We report a novel superconducting (SC) and antiferromagnetic (AF) hybrid state in SrFe2As2 revealed by 75As nuclear magnetic resonance (NMR) experiments on a single crystal under highly hydrostatic pressure up to 7 GPa. The NMR spectra at 5.4 GPa indicate simultaneous development of the SC and AF orders below 30 K. The nuclear spin-lattice relaxation rate in the SC domains shows a substantial residual density of states, suggesting proximity effects due to spontaneous formation of a nano-scale SC/AF hybrid structure. This entangled behavior is a remarkable example of a self-organized heterogeneous structure in a clean system.