Al-Based Few-Hydrogen Metal-Bonded Perovskite High-$T_c$ Superconductor Al$_4$H up to 54 K under Atmospheric Pressure

TL;DR

This paper proposes a novel Al-based perovskite hydride superconductor, Al4H, predicted to achieve a high critical temperature of 54 K at atmospheric pressure, addressing the challenge of high-pressure requirements in existing high-$T_c$ materials.

Contribution

The study introduces a new design strategy for ambient-pressure high-$T_c$ superconductors using metal-bonded perovskite hydrides, specifically Al4H, with improved ductility and high critical temperature.

Findings

Al4H predicted to have $T_c$ up to 54 K at atmospheric pressure

Constructed as a novel few-hydrogen metal-bonded perovskite hydride

Based on Migdal-Eliashberg theory, indicating structural stability and high $T_c$

Abstract

Multi-hydrogen lanthanum hydrides have shown the highest critical temperature $T_c$ at 250-260 K under 170-200 GPa. However, such high pressure is a great challenge for sample preparation and practical application. To address this challenge, we propose a novel design strategy for ambient-pressure high-$T_c$ superconductors by constructing new few-hydrogen metal-bonded perovskite hydrides, such as Al-based superconductor $\rm {Al_4H}$, with better ductility than the well-known multi-hydrogen, cuprate and Fe-based superconductors. Based on the Migdal-Eliashberg theory, we predict that the structurally stable $\rm {Al_4H}$ has a favorable high $T_c$ up to 54 K under atmospheric pressure, similar to SmOFeAs.