Unconventional superconductivity without doping in infinite-layer nickelates under pressure

High-temperature unconventional superconductivity quite generically emerges from doping a strongly correlated parent compound, often (close to) an antiferromagnetic insulator. The recently developed dynamical vertex approximation is a state-of-the-art technique that has quantitatively predicted the superconducting dome of nickelates. Here, we apply it to study the effect of pressure in the infinite-layer nickelate Sr x Pr1-x NiO2. We reproduce the increase of the critical temperature (T c ) under pressure found in experiment up to 12 GPa. According to our results, T c can be further increased with higher pressures. Even without Sr-doping the parent compound, PrNiO2, will become a high-temperature superconductor thanks to a strongly enhanced self-doping of the Ni d x 2 - y 2 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${d}_{{x}<^>{2}-{y}<^>{2}}$$\end{document} orbital under pressure. With a maximal T c of 100 K around 100 GPa, nickelate superconductors can reach that of the best cuprates.The authors theoretically study the pressure dependence of the phase diagram of the nickelate PrNiO2 with and without Sr doping. At high pressure, they find that the superconducting dome is significantly enhanced in both T c and doping-range of superconductivity compared with ambient pressure, with a maximal T c of 100 K around 100 GPa in absence of external doping.