Emergence of superconductivity in doped H2O ice at high pressure

José A Flores-Livas,Miglė Graužinytė,Arkadiy Davydov,Miguel A L Marques,Antonio Sanna,Stefan Goedecker

doi:10.1038/s41598-017-07145-4

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 H2O, 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 150 GPa. In view of the vast number of hydrides that are strongly covalent bonded, but that remain insulating up to rather large pressures, our results open a series of new possibilities in the quest for novel high-temperature superconductors.

Highlights

The theoretical prediction[1] and subsequent experimental discovery[2] of superconductivity in H3S at 200 GPa, with the record critical temperature (TC) of 203 K, rekindled the century-old dream of a room temperature superconductor
Many chemical compounds containing hydrogen only metallize at extremely high pressures
Despite its simple chemical formula, H2O appears in nature in all three common states of matter and it has one of the most complex phase diagrams known ref

Summary

Introduction

The theoretical prediction[1] and subsequent experimental discovery[2] of superconductivity in H3S at 200 GPa, with the record critical temperature (TC) of 203 K, rekindled the century-old dream of a room temperature superconductor. The aim of this research effort is to better understand how high critical temperatures can be achieved and if the same mechanisms can work at lower pressures and/or even higher (room temperature) TC in other materials. In this quest for novel high-TC superconductors, many other materials have been proposed. It is well known that by introducing enough electronor hole-donating impurities one can render a semiconducting system metallic and even superconducting. In this work we follow this strategy, and investigate if the combination of doping and high pressure can be used to obtain high-temperature superconductivity in hydrides. Its metallization was predicted to occur beyond 5 TPa55–58

Methods

Results

Conclusion