Emergence of superconductivity in doped H$_2$O ice at high pressure

TL;DR

This study demonstrates that doping ice with nitrogen under high pressure can induce superconductivity at around 60 K, revealing new pathways for high-temperature superconductor discovery in hydrides.

Contribution

It introduces nitrogen doping as a method to induce superconductivity in high-pressure ice, a novel approach for hydride superconductors.

Findings

Doped ice becomes superconducting at 150 GPa with T_c around 60 K.

Nitrogen is identified as an effective dopant for inducing superconductivity.

Doping levels of a few percent are sufficient to achieve superconductivity.

Abstract

We investigate the possibility of achieving high-temperature superconductivity in hydrides under pressure by inducing metallization of otherwise insulating phases through doping, a path previously used to render standard semiconductors superconducting at ambient pressure. Following this idea, we study H$_2$O, one of the most abundant and well-studied substances, we identify nitrogen as the most likely and promising substitution/dopant. We show that for realistic levels of doping of a few percent, the phase X of ice becomes superconducting with a critical temperature of about 60 K at 150GPa. In view of the vast number of hydrides that are strongly covalent bonded, but that remain insulating until rather large pressures, our results open a series of new possibilities in the quest for novel high-temperature superconductors.