Orbital-selective superconductivity in a two-band model of infinite-layer nickelates

In the present Rapid Communication, we explore superconductivity in $\mathrm{Nd}\mathrm{Ni}{\mathrm{O}}_{2}$ and $\mathrm{La}\mathrm{Ni}{\mathrm{O}}_{2}$ employing a first-principles derived low-energy model Hamiltonian, consisting of two orbitals: Ni ${x}^{2}\ensuremath{-}{y}^{2}$, and an axial orbital. The axial orbital is constructed out of Nd/La $d$, Ni $3{z}^{2}\ensuremath{-}{r}^{2}$, and Ni $s$ characters. Calculation of the superconducting pairing symmetry and pairing eigenvalue of the spin-fluctuation mediated pairing interaction underlines the crucial role of the interorbital Hubbard interaction in superconductivity, which turns out to be orbital selective. The axial orbital brings in material dependence to the problem, making $\mathrm{Nd}\mathrm{Ni}{\mathrm{O}}_{2}$ different from $\mathrm{La}\mathrm{Ni}{\mathrm{O}}_{2}$, thereby controlling the interorbital Hubbard interaction-assisted superconductivity.