Orbital Selective Superconductivity in a Two-band Model of Infinite-Layer Nickelates

In the present study, we explore superconductivity in NdNiO${}_2$ and LaNiO${}_2$ employing a first-principles derived low-energy model Hamiltonian, consisting of two orbitals: Ni $x^2$-$y^2$, and an {\it axial} orbital. The {\it axial} orbital is constructed out of Nd/La $d$, Ni 3$z^2$-$r^2$ 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 inter-orbital Hubbard interaction in superconductivity, which turns out to be orbital-selective. The axial orbital brings in materials dependence in the problem, making NdNiO${}_2$ different from LaNiO${}_2$, thereby controlling the inter-orbital Hubbard interaction assisted superconductivity.