Conductivity of infinite-layer NdNiO2 as a probe of spectator bands

Using a density functional theory (DFT) plus dynamical mean-field theory methodology, we compute the many-body electronic structure and optical conductivity of NdNiO2 under the influence of large scattering rates on the Nd(5d) bands and including dynamical interactions on the Nd(5d) orbitals with shifts of the Nd-Ni d-level energy difference. We find a robust conducting pathway in the out-of-plane direction arising from strong hybridization between the Ni-dz2 and Nd(5d) orbitals. This pathway can be "short-circuited" if this hybridization is suppressed through large electronic scattering rates but is not reduced to zero even by very large beyond-DFT shifts of the Nd-Ni d-level energy splitting. The computed in-plane conductivity for NdNiO2 predicts the material to be a "good metal" in contrast to experiments indicating the material is a "bad metal" or "weak insulator". Our results motivate future experiments measuring the c-axis resistivity as a proxy for the spectator bands and suggests the essential difference between the infinite-layer nickelates and the cuprates is dimensionality of their electronic structures.