Prediction of $s^\pm$-wave superconductivity enhanced by electronic doping in trilayer nickelates La$_4$Ni$_3$O$_{10}$ under pressure

TL;DR

This study uses ab initio and RPA methods to explore superconductivity in trilayer La4Ni3O10 under pressure, revealing an s±-wave pairing mechanism enhanced by electron doping and predicting a spin-density-wave state.

Contribution

It provides a detailed theoretical analysis of the electronic structure and superconducting pairing in La4Ni3O10, highlighting the role of doping and multilayer effects in superconductivity.

Findings

Superconductivity is induced in the s±-wave channel due to Fermi surface nesting.

Maximum pairing strength occurs at about 6.7% electron doping.

A spin-density-wave state with in-plane order is predicted in La4Ni3O10.

Abstract

Motivated by the recently reported signatures of superconductivity in trilayer La$_4$Ni$_3$O$_{10}$ under pressure, we comprehensively study this system using {\it ab initio} and random-phase approximation techniques. Without electronic interactions, the Ni $d_{3z^2-r^2}$ orbitals show a bonding-antibonding and nonbonding splitting behavior via the O $p_z$ orbitals inducing a ``trimer'' lattice in La$_4$Ni$_3$O$_{10}$, analogous to the dimers of La$_3$Ni$_2$O$_{7}$. The Fermi surface consists of three electron sheets with mixed $e_g$ orbitals, and a hole and an electron pocket made up of the $d_{3z^2-r^2}$ orbital, suggesting a Ni two-orbital minimum model. In addition, we find that superconducting pairing is induced in the $s^{\pm}$-wave channel due to partial nesting between the {\bf M}=$(\pi, \pi)$ centered pockets and portions of the Fermi surface centered at the {\bf $\Gamma$}=$(0, 0)$ point. With changing electronic density $n$, the $s^\pm$ instability remains leading and its pairing strength shows a dome-like behavior with a maximum around $n = 4.2$ ($\sim 6.7\%$ electron doping). The superconducting instability disappears at the same electronic density as that in the new 1313 stacking La$_3$Ni$_2$O$_7$, correlated with the vanishing of the hole pocket that arises from the trilayer sublattice, suggesting that the high-$T_c$ superconductivity of La$_3$Ni$_2$O$_7$ may $not$ originate from a trilayer- and single-layer structure. Furthermore, we predict an interesting spin-density-wave state in La$_4$Ni$_3$O$_{10}$ with an in-plane ($\pi$, $\pi$) order and antiferromagnetic coupling between the top and bottom Ni layers, while the middle layer has spin zero.