Superconductivity in infinite-layer nickelates: similarities and differences from cuprates

The electronic structure of infinite-layer nickelates RNiO₂ (R= La, Nd) is revisited in light of the discovery of superconductivity in Sr-doped NdNiO₂. From a comparison to their cuprate counterpart CaCuO₂, we derive essential facts related to their electronic structures, in particular, the values for hopping parameters and energy splittings, and the influence of the spacer cation. From this detailed comparison, we comment on expectations in regards to superconductivity. In particular, both materials exhibit a large ratio of longer-range hopping to nearest-neighbor hopping which should be conducive for superconductivity.