A recent experiment [X. Ding et al., Nature 615, 50 (2023)] indicates that superconductivity in nickelates is restricted to a narrow window of hydrogen concentration: 0.22 < x < 0.28 in Nd0.8Sr0.2NiO2Hx. This reported necessity of hydrogen suggests that it plays a crucial role for superconductivity, as it does in the vast field of hydride superconductors. Using density-functional theory and its extensions, we explore the effect of topotactic hydrogen on the electronic structure and phonon-mediated superconductivity in nickelate superconductors. Our calculations show that the electron-phonon coupling in hydrogen-intercalated nickelates is not strong enough to drive the electron pairing, and thus cannot explain the reported superconductivity.
@article{arxiv.2304.03599,
title = {Absence of electron-phonon-mediated superconductivity in hydrogen-intercalated nickelates},
author = {Simone Di Cataldo and Paul Worm and Liang Si and Karsten Held},
journal= {arXiv preprint arXiv:2304.03599},
year = {2023}
}