We study superconductivity in the superionic phase of the clathrate hydride Li2MgH16, where hydrogen ions diffuse among the lattice formed by lithium and magnesium ions. By employing the stochastic path-integral approach, we non-perturbatively take into account the effects of quantum diffusion and anharmonic vibrations. Our calculations reveal strong electron-ion coupling (λ(0) = 3.7) and a high superconducting transition temperature (Tc) of 277 K under 260 GPa, at which the material is still superionic. Tc is significantly suppressed compared with the result Tc = 473 K obtained from the conventional approach based on the harmonic approximation. Our study, based on a first-principles approach applicable to superionic systems, indicates that the superconductivity and superionicity can coexist in Li2MgH16.
@article{arxiv.2305.04875,
title = {Coexistence of Superconductivity and Superionicity in Li$_2$MgH$_{16}$},
author = {Haoran Chen and Junren Shi},
journal= {arXiv preprint arXiv:2305.04875},
year = {2024}
}