Unconventional superconductivity without doping in infinite-layer nickelates under pressure

Abstract

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_xPr_1-xNiO₂. 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 $d_{x^2-y^2}$ orbital under pressure. With a maximal T_c of 100 K around 100 GPa, nickelate superconductors can reach that of the best cuprates.