s±-wave superconductivity in pressurized La4Ni3O10

Recently, evidence of superconductivity (SC) has been reported in pressurized La4Ni3O10. Here we study its possible pairing mechanism and pairing symmetry. Through fitting the density-functional-theory band structure, we provide a six-orbital tight-binding model. In comparison with the band structure of La3Ni2O7, the additional nonbonding dz2 band is important to the pairing mechanism here. When the multiorbital Hubbard interactions are included, our random-phase-approximation based study yields an s +/--wave SC. The dominant Fermi-surface nesting with vector Q1 approximate to (n, n) is between the gamma pocket contributed by the bonding dz2 band top and the alpha 1 pocket contributed by the nonbonding dz2 band bottom, leading to the strongest pairing amplitude and opposite gap signs within the two regimes. The dominant real-space pairing is the interlayer dz2-orbital pairing. This s +/--wave pairing pattern is insensitive to the band details. Upon electron doping, the Tc would increase promptly before the system enters the N & eacute;el-ordered spin-density-wave phase.