Fig. 2: The spectrum of ordering instabilities in pristine non-magnetic LaNiO₂.

Momentum dependence of the largest ordering instability \({{{\Lambda }}}_{F}^{0}({{{{{{{\bf{q}}}}}}}},\omega =0)\) for pristine LaNiO₂ in the non-magnetic phase for a various slices along q_z, and b in the Γ and Z planes of the Brillouin zone. The red and blue “x” marks denote the critical and sub-critical instability momenta Q^*, respectively. The black dashed line gives the boundary of the Brillouin zone. The color bars indicate the instability strength. c Density of instabilities with the two Van Hove-like singularities and the step edge indicated by Roman numerals \({\mathbb{I}}\), \({\mathbb{II}}\), and \({\mathbb{III}}\). The inset in c shows the regions of origin in \({{{\Lambda }}}_{F}^{0}({{{{{{{\bf{q}}}}}}}},\omega =0)\) of the various marked peaks.