Computational Materials Discovery for Lanthanide Hydrides at high pressure: predicting High Temperature superconductivity

TL;DR

This paper presents a first-principles computational platform incorporating many-body corrections to predict and analyze the superconducting properties of lanthanide hydrides, specifically CeH$_9$, at high pressures, aiming to discover new high-temperature superconductors.

Contribution

It introduces a detailed first-principles calculation method with many-body corrections for studying hydrogen-rich superhydrides, improving T$_c$ predictions and understanding their superconductivity mechanisms.

Findings

Many-body corrections significantly increase predicted T$_c$ values.

The computational approach aligns well with experimental T$_c$ observations.

The platform facilitates exploration of superhydrides at feasible pressures.

Abstract

Hydrogen-rich superhydrides are believed to be very promising high-T$_c$ superconductors, with experimentally observed critical temperatures near room temperature, as shown in recently discovered lanthanide superhydrides at very high pressures, e.g. LaH$_{10}$ at 170 GPa and CeH$_9$ at 150 GPa. With the motivation of discovering new hydrogen-rich high-T$_c$ superconductors at lowest possible pressure, quantitative theoretical predictions are needed. In these promising compounds, superconductivity is mediated by the highly energetic lattice vibrations associated with hydrogen and their interplay with the electronic structure, requiring fine descriptions of the electronic properties, notoriously challenging for correlated $f$ systems. In this work, we propose a first-principles calculation platform with the inclusion of many-body corrections to evaluate the detailed physical properties of the Ce-H system and to understand the structure, stability and superconductivity of CeH$_9$ at high pressure. We report how the prediction of T$_c$ is affected by the hierarchy of many-body corrections, and obtain a compelling increase of T$_c$ at the highest level of theory, which goes in the direction of experimental observations. Our findings shed a significant light on the search for superhydrides in close similarity with atomic hydrogen within a feasible pressure range. We provide a practical platform to further investigate and understand conventional superconductivity in hydrogen rich superhydrides.