paper

Universal quasi-degenerate orbital origin of two-dome phases in iron pnictide superconductors

arXiv:2512.20284 · doi:10.1103/cdgy-gwyj

Abstract

A series of experiments revealed that novel bipartite magnetic and superconducting (SC) phases widely exist in the phase diagrams of iron pnictides and chalcogenides. Nevertheless, the origin of the two-dome magnetic and SC phases in iron-based compounds remains unclear. Here we theoretically investigated the electronic structures, magnetic and SC properties of three representative iron-based systems, i.e. LaFeAsOH, LaFeAsPO and KFeAs. We propose a unified quasi-degenerate orbital mechanism for the emergence of the two-dome parent magnetic/structural phase and the subsequent two-dome SC phase. It is found that the degenerate in-plane anisotropic orbitals dominate the first magnetic/structural and SC phases, while in-plane isotropic orbitals or with quasi-degeneracy originating from quasi-symmetry drive the emergence of the second magnetic/SC dome phase. Moreover, a matching rule of spin and orbital modes for SC pairing state is proposed in multi-orbital iron-based systems. These results imply an orbital-driven mechanism as well as an orbital-selective scenario, and shed light on the understanding of the multi-dome magnetic and SC phases in multi-orbital systems.

36 pages, 16 figures; this article supersedes arXiv: 1701.02500

References in corpus (25)

Cited by in corpus (1)