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THU: Thursday Contributed Sessions
THU 9: Correlated Quantum Matter: Contributed Session to Symposium II
THU 9.1: Talk
Thursday, September 11, 2025, 14:15–14:30, ZHG101
Intertwined superconductivity and orbital selectivity in a three-orbital Hubbard model for the iron pnictides — Vito Marino1,2, Alberto Scazzola3, Federico Becca4, Massimo Capone1, and •Luca F. Tocchio2 — 1International School for Advanced Studies (SISSA) and CNR-IOM, Trieste, Italy — 2Institute for Condensed Matter Physics and Complex Systems, DISAT, Politecnico di Torino, Italy — 3Department of Electronics and Telecommunications, Politecnico di Torino, Italy — 4Dipartimento di Fisica, University of Trieste, Italy
We study a three-orbital Hubbard-Kanamori model relevant for iron-based superconductors using variational wave functions explicitly including spatial correlations and electron pairing. We span the nonmagnetic sector from filling n=4, which is representative of undoped iron-based superconductors, to n=3, where a Mott insulating state with each orbital at half filling is found. In the strong-coupling regime, when the electron density is increased, we find a spontaneous differentiation between the occupation of dxz and dyz orbitals, leading to an orbital-selective state with a nematic character that becomes stronger at increasing density. One of these orbitals stays half filled for all densities while the other one hosts (together with the dxy orbital) the excess of electron density. Most importantly, in this regime long-range pairing correlations appear in the orbital with the largest occupation. Our results highlight a strong link between orbital-selective correlations, nematicity, and superconductivity, which requires the presence of a significant Hund’s coupling.
Keywords: Strongly correlated quantum systems; High-temperature superconductivity; Iron-based superconductors; Monte Carlo methods; Hubbard model