Doping dependence of electronic structure of infinite-layer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>NdNiO</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:math>
Zhao Liu, Chenchao Xu, Chao Cao, Wei Zhu, Zhengfei Wang, Jinlong Yang
Abstract
We investigate the electronic structure of nickelate superconductor ${\mathrm{NdNiO}}_{2}$ upon hole doping, by means of density-functional theory and dynamical mean-field theory. We demonstrate the strong intrinsic hybridization between strongly correlated states formed by Ni-$3{d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ orbital and itinerant electrons due to Nd-$5d$ and Ni-$3{d}_{{z}^{2}}$ orbitals, producing a valence-fluctuating correlated metal as the normal state of hole-doped ${\mathrm{NdNiO}}_{2}$. The Hund's rule appears to play a dominating role on multiorbital physics in the lightly doped compound, while its effect is gradually reduced by increasing the doping level. Crucially, the hole-doping leads to intricate effects on Ni-$3d$ orbitals, such as a nonmonotonic change of electron occupation in lightly doped level, and a flipping orbital configuration in the overdoped regime. Additionally, we also map out the topology of Fermi surface at different doping levels. These findings render a preferred window to peek into electron pairing and superconductivity.