Emergence of superconductivity in the canonical heavy-electron metal YbRh2Si2

TL;DR

This study reports the discovery of heavy-electron superconductivity in YbRh2Si2 at ultra-low temperatures, driven by quantum criticality, with evidence of nuclear antiferromagnetic order influencing electronic properties.

Contribution

It provides the first evidence of superconductivity emerging from quantum criticality in a canonical heavy-electron metal, linked to nuclear magnetic order.

Findings

Nuclear antiferromagnetic order develops above 2 mK.

Heavy-electron superconductivity appears below 2 mK.

Quantum criticality can induce superconductivity in heavy-electron systems.

Abstract

We report magnetic and calorimetric measurements down to T = 1 mK on the canonical heavy-electron metal YbRh2Si2. The data reveal the development of nuclear antiferromagnetic order slightly above 2 mK. The latter weakens the primary electronic antiferromagnetism, thereby paving the way for heavy-electron superconductivity below Tc = 2 mK. Our results demonstrate that superconductivity driven by quantum criticality is a general phenomenon.