Absence of electron-phonon-mediated superconductivity in hydrogen-intercalated nickelates

Simone Di Cataldo; Paul Worm; Liang Si; Karsten Held

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arXiv · 2304.03599

Absence of electron-phonon-mediated superconductivity in hydrogen-intercalated nickelates

Simone Di Cataldo·Paul Worm·Liang Si·Karsten Held

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Abstract

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 Nd$_{0.8}$Sr$_{0.2}$NiO$_{2}$H$_{x}$. 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.

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Simone Di Cataldo, Paul Worm, Liang Si, Karsten Held. 2023-04-07. Absence of electron-phonon-mediated superconductivity in hydrogen-intercalated nickelates. https://arxiv.org/abs/2304.03599

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