Superconducting Instabilities in Strongly Correlated Infinite-Layer Nickelates

Abstract

The discovery of superconductivity in infinite-layer nickelates has added a new family of materials to the fascinating growing class of unconventional superconductors. By incorporating the strongly correlated multiorbital nature of the low-energy electronic degrees of freedom, we compute the leading superconducting instability from magnetic fluctuations relevant for infinite-layer nickelates. Specifically, by properly including the doping dependence of the Ni ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ and ${d}_{{z}^{2}}$ orbitals as well as the self-doping band, we uncover a transition from $d$-wave pairing symmetry to nodal ${s}_{\ifmmode\pm\else\textpm\fi{}}$ superconductivity, driven by strong fluctuations in the ${d}_{{z}^{2}}$-dominated orbital states. We discuss the properties of the resulting superconducting condensates in light of recent tunneling and penetration depth experiments probing the detailed superconducting gap structure of these materials.