2024/09/15 by Hao Chen, Hui Wang, Chen, Haoran +3 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Hydrogen Storage and Materials #Materials Science (cond-mat.mtrl-sci) #Physics of Superconductivity and Magnetism #Superconducting Materials and Applications #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2409.09836
openalex publication_date 2024/09/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Various clathrate superhydride superconductors have been found to possess hydrogen deficiency in experimental samples, while their impacts on superconductivity are often neglected. In this study, we investigate the superconductivity of lanthanum superhydride with hydrogen deficiency (LaH10-δ) from first principles using path-integral approaches. Under the effects of thermal and quantum fluctuations, hydrogen vacancies are found to diffuse within the system, leading to modifications in ion vibrations, electronic structure and electron-phonon coupling. These changes result in a non-monotonic dependence of superconducting transition temperature (Tc) on the vacancy concentration (δ). By comparing the experimental and theoretical equations of state, we suggest that δ varies across samples under different pressures. This explains the positive pressure dependence of Tc in experiments below 150 GPa. Remarkably, within this pressure range, we find that Tc could be further raised by increasing δ.