[9a-A31-1~13] 11.1 Fundamental properties

9:45 AM - 10:00 AM JST(12:45 AM - 1:00 AM UTC)

[9a-A31-4] Theoretical study of the hierarchical pairing in bilayer nickelate superconductor employing variational Monte Carlo method

Watanabe Hiroshi¹, 〇Hirofumi Sakakibara², Kazuhiko Kuroki³ (1.Nihon Univ., 2.Tottori Univ. AMES, 3.Univ. of Osaka)

Keywords:

superconductor,high-Tc superconductor,nickelate superconductor

The superconducting pairing mechanism of the bilayer nickelate La₃Ni₂O₇ under high pressure remains a subject of ongoing debate, demanding theoretical analyses that can comprehensively treat both weak- and strong-correlation regimes. In this study, we investigate a bilayer two-orbital Hubbard model using the variational Monte Carlo method. Our analysis reveals a hierarchical pairing structure, where the dz2 orbital gap function—induced by a large interlayer hopping—takes the lead, with the dx2-y2 orbital following it. The resulting s± wave symmetry is found to be robust against parameter variations.