Superconductivity in La₄Ni₃O₁₀ Under Pressure

Recently, signature of superconductivity (SC) in the trilayer compound La₄Ni₃O₁₀ has ignited significant interest. In this study, we propose a trilayer Eg orbital t-J∥-J⊥ model to gain insights into the superconducting behavior in this material. In the strong coupling limit, each layer is described by a t-J∥ model with intra-layer exchange J∥, while electrons can hop between layers and interact through inter-layer exchange J⊥. Notably, the inner-layer 3dz²-orbital electrons exhibit the potential to form bonding bands with those in the upper or lower layer. The superconducting behavior is predominantly driven by the 3dz² orbital, resulting in an intra-layer extended s-wave pairing in the outer layers, along with an inter-layer pairing. Furthermore, electron doping tends to enhance the superconductivity, while hole doping suppresses it. These findings shed light on the intriguing SC of La₄Ni₃O₁₀ and its response to charge doping.