Superconductivity in La4Ni3O10 under pressure

Abstract

The discovery of superconductivity (SC) in the trilayer nickelate compound La4Ni3O10 under pressure has generated significant interest. In this work, we propose a trilayer two Eg-orbital t−J∥−J⊥ model to investigate the microscopic origin of SC in this system. In the strong-coupling regime, each layer is governed by a t−J∥ model with intralayer antiferromagnetic exchange J∥, while electrons are allowed to hop between layers, interacting via interlayer exchange J⊥. The inner-layer 3dz2-orbital electrons tend to form bonding states with those in the neighboring layers, leading to redistribution of the electron densities. The numerical simulation results indicate that SC is predominantly mediated by the 3dz2 orbital, characterized by an intralayer extended s-wave pairing in the outer layers, accompanied by an interlayer pairing with opposite sign. Furthermore, we find that electron doping enhances SC, while hole doping tends to suppress it. These findings provide new insights into the SC mechanisms of La4Ni3O10 and its sensitivity to charge doping.

Source-reported materials — not catalogue approval

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