Isotropic Cooper Pairs with Emergent Sign Changes in Single-Layer Iron Superconductor

Abstract

We model a single layer of heavily electron-doped FeSe by spin-1/2 moments over a square lattice of iron atoms that include the 3d xz and 3d yz orbitals, at strong on-site Coulomb repulsion. Above half filling, we find emergent hole bands below the Fermi level at the center of the one-iron Brillouin zone in a half metal state characterized by hidden magnetic order and by electron-type Fermi surface pockets at wavenumbers that double the unit cell along the principal axes. "Replicas" of the emergent hole bands exist at lower energy in the two-iron Brillouin zone. Exact calculations with two mobile electrons find evidence for isotropic Cooper pairs that alternate in sign between the electron bands and the emergent hole bands.

10 pages, 3 figures, notes possibility of hidden magnetic order in intercalated FeSe

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Cited by in corpus (5)

• Spin Resonances in Iron-Selenide High-Tc Superconductors by Proximity to Hidden Spin Density Wave
• Superconductivity by Hidden Spin Fluctuations in Electron-Doped Iron Selenide
• Fermi surface pockets in electron-doped iron superconductor by Lifshitz transition
• Particle-Hole Transformation in Strongly-Doped Iron-Based Superconductors
• Quantum-Critical Spin-Density Waves in Iron-Selenide High-Tc Superconductors