Pressure induced superconductivity on the border of magnetic order in MnP

TL;DR

This paper reports the discovery of pressure-induced superconductivity in MnP near a magnetic quantum critical point, highlighting unconventional pairing and non-Fermi-liquid behavior.

Contribution

It presents the first Mn-based superconductor discovered near a magnetic instability, linking superconductivity to quantum fluctuations.

Findings

Superconductivity appears near 8 GPa where magnetic order vanishes.

Normal-state transport shows non-Fermi-liquid behavior.

Effective mass of quasi-particles is dramatically enhanced near the critical pressure.

Abstract

We report the discovery of superconductivity on the border of long-range magnetic order in the itinerant-electron helimagnet MnP via the application of high pressure. Superconductivity with Tsc~1 K emerges and exists merely near the critical pressure Pc~8 GPa, where the long-range magnetic order just vanishes. The present finding makes MnP the first Mn-based superconductor. The close proximity of superconductivity to a magnetic instability suggests an unconventional pairing mechanism. Moreover, the detailed analysis of the normal-state transport properties evidenced non-Fermi-liquid behavior and the dramatic enhancement of the quasi-particle effective mass near Pc associated with the magnetic quantum fluctuations.