A "road-map" of Nickelate superconductivity

We comment on the electronic structure of Nickelate system $NdNi{O}_2$ which shows superconductivity on doping. The doped system $N{d}_{0.8}S{r}_{0.2}Ni{O}_2$ shows (most probably unconventional) superconductivity with transition temperatures ranging from $9K$ to $15K$\cite{dang}. The resistivity of the parent compound $NdNi{O}_2$ shows a minimum at around 60K, and an up-turn at lower temperatures. In the current understanding it is thought to be originating from a Kondo like coupling between mobile d-states of the $Nd5d$ bands and un-paired electrons in $Ni3d_{x^2-y^2}-O2p$ hybrid orbitals of $N{i}^{1+}$ and $O^{2-}$ions. In this note we offer alternative possibilities of the observed resistance minimum in $LaNi{O}_2$. We attempt to construct a “road-map” of various possibilities to comprehend the observed behaviour and suggest further experiments to prove or disprove a given explanation. We also compare and contrast Nickelates with Cuprates. Comparison points towards unconventional superconductivity in Nickelates.