2024/03/03 by Adam Denchfield, Denchfield, Adam, Francesco Belli +7
Materials Science · #FOS: Physical sciences #Hydrogen Storage and Materials #Materials Science (cond-mat.mtrl-sci) #Nuclear Materials and Properties #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2403.01350
openalex publication_date 2024/03/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We explore electronic and structural properties of Fm3m Lu-H-N structures with specific N,H ordering as plausible candidates for near-ambient superconductivity possibly originating from their remarkably narrow hydrogen-based bands at the Fermi level. Although LuH2.875N0.125 exhibits an instability persisting up to 17 GPa, it is anharmonically stable near ambient pressure when accounting for quantum nuclear effects. The presence of flat bands near EF is understood to arise from destructive quantum interference between N-p and surrounding H-s orbitals, with certain types of defects leaving the flat bands unaffected. The results suggest there is an optimal pressure near ambient where the superconducting Tc is maximized in this structure by anharmonically-stabilized low-frequency and non-adiabatically coupled high-frequency hydrogen modes. Despite the metastability of this structure, its electronic properties and dynamical stability when calculated beyond a classical harmonic approach can explain the reported near-ambient superconductivity in Lu-H-N.