Variational Quantum Monte Carlo investigations of the superconducting pairing in La₃Ni₂O₇

2025/05/12 by Liu, Yi-Qun, Wang, Da, Wang, Qiang-Hua · 1 citation
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)

paper · doi:10.48550/arxiv.2505.07341

Abstract

We investigate the pairing symmetry in the novel superconductor La₃Ni₂O₇ under pressure by the non-perturbative variational quantum Monte Carlo. Within the bilayer Hubbard model and extended t-J model with two orbitals in the E_g doublet, we find the local strong correlation triggers s_±-wave Cooper pairing, with sign change of the gap function among the various Fermi pockets, while the d_x²-y²-wave pairing is generically disfavored. This is in agreement with the results from functional renormalization group applied in the weak up to moderate correlation limit. We find the 3d_3z²-r² orbital plays a leading role in the superconducting pairing. We also demonstrate the finite intra-orbital double occupancy even in the strong correlation limit, shedding light on the itinerant versus local moment picture of the electrons in this material.

Citations

• Type II t-J model in charge transfer regime in bilayer La₃Ni₂O₇ and trilayer La₄Ni₃O₁₀
• Pressure-enhanced spin-density-wave transition in double-layer nickelate La₃Ni₂O_7-δ
• Electron-phonon mediated superconductivity in La₆Ni₅O₁₂ nickel oxides
• Superconductivity in the pressurized nickelate La₃Ni₂O₇ in the vicinity of a BEC-BCS crossover
• Strong pairing from small Fermi surface beyond weak coupling: Application to La₃Ni₂O₇
• Signatures of superconductivity near 80 K in a nickelate under high pressure

Cited by

• Strain-Engineered Electronic Structure and Superconductivity in La₃Ni₂O₇ Thin Films

Related

• Interlayer Pairing in Bilayer Nickelates
• Variation Monte Carlo Study on the bilayer t-J_∥-J_⊥ model for La₃Ni₂O₇
• Examining density wave correlations in high pressure \rmLa₃Ni₂O₇ through variational Monte Carlo
• Incommensurate spin fluctuations and competing pairing symmetries in La₃Ni₂O₇
• Orbital-selective correlation effects and superconducting pairing symmetry in a multiorbital t-J model for bilayer nickelates