Possible High Tc Superconductivity in La3Ni2

Inspired by a recent experiment showing that ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ exhibits high ${T}_{c}$ superconductivity under high pressure, we theoretically revisit the possibility of superconductivity in this material. We find that superconductivity can take place, which is somewhat similar to that of the bilayer Hubbard model consisting of the Ni $3{d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ orbitals. Although the coupling with the $3{d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ orbitals degrades superconductivity, ${T}_{c}$ can still be high enough to understand the experiment thanks to the very high ${T}_{c}$ reached in the bilayer Hubbard model.