Electronic Properties, Band Structure, and Fermi Surface Instabilities of ${\mathrm{Ni}}^{1+}/{\mathrm{Ni}}^{2+}$ Nickelate ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{6}$, Isoelectronic with Superconducting Cuprates

Electronic Properties, Band Structure, and Fermi Surface Instabilities of ${Ni}^{1 +} / {Ni}^{2 +}$ Nickelate ${La}_{3} {Ni}_{2} O_{6}$ , Isoelectronic with Superconducting Cuprates

Viktor V. Poltavets, Martha Greenblatt, Gerhard H. Fecher, and Claudia Felser

Phys. Rev. Lett. 102, 046405 – Published 28 January 2009

Abstract

Electronic structure calculations were performed for the mixed-valent ${Ni}^{1 +} / {Ni}^{2 +}$ nickelate ${La}_{3} {Ni}_{2} O_{6}$ , which exhibits electronic instabilities of the Fermi surface similar to that of the isostructural superconducting ${La}_{2} {CaCu}_{2} O_{6}$ cuprate. ${La}_{3} {Ni}_{2} O_{6}$ shows activated hopping, which fits to Mott’s variable-range-hopping model with localized states near the Fermi level. However, a simple local spin density approximation calculation leads to a metallic ground state. The calculations including local density $approximation + Hubbard$ $U$ and hybrid functionals indicate a multiply degenerate magnetic ground state. For electron-doped ${La}_{2} {ZrNi}_{2} O_{6}$ , which is isoelectronic with ${La}_{2} {CaCu}_{2} O_{6}$ , an antiferromagnetic insulating ground state is found when correlations are included. The nickelates are thus ideal model systems for a deeper understanding of correlated transition metal compounds, magnetism, and superconductivity.