Correlations tune the electronic structure of pentalayer nickelates into the superconducting regime

Motivated by the recent discovery of superconductivity in the pentalayer nickelate Nd6Ni5O12 [G. A. Pan et al., Nat. Mater. 21, 160 (2022)], we calculate its electronic structure and superconducting critical temperature. We find that electronic correlations are essential for pushing Nd6Ni5O12 into the superconducting doping range as they shift the electron pockets above the Fermi energy. As a consequence, Nd6Ni5O12 can be described with a single d(x2- y2) orbital per Ni. We predict the pentalayer to be overdoped; further improvements in T-c can be expected for a few additional layers. Instead, for the bilayer nickelate Nd3Ni2O6 we find correlations to drive the system into a three-orbital regime also involving the Ni d(xz, yz) states. We suggest, however, that single-orbital physics with optimal doping can be restored by substituting 60% of the trivalent Nd or La by tetravalent Zr.

Automated summary

Motivated by recent discoveries in nickelate compounds, this study investigates the effect of electronic correlations on their superconducting properties. For the pentalayer nickelate Nd6Ni5O12, correlations are found to push the material into the superconducting doping range, while for the bilayer nickelate Nd3Ni2O6, correlations result in a three-orbital regime. The findings suggest that substituting ions can restore the single-orbital physics with optimal doping.