Isostructural spin-density-wave and superconducting gap anisotropies in iron-arsenide superconductors

Abstract

When passing through a phase transition, electronic system saves energy by opening energy gaps at the Fermi level. Delineating the energy gap anisotropy provides insights into the origin of the interactions that drive the phase transition. Here, we report the angle-resolved photoemission spectroscopy (ARPES) study on the detailed gap anisotropies in both the tetragonal magnetic and superconducting phases in Sr${}_{1-x}$Na${}_x$Fe${}_2$As${}_2$. First, we found that the spin-density-wave (SDW) gap is strongly anisotropic in the tetragonal magnetic phase. The gap magnitude correlates with the orbital character of Fermi surface closely. Second, we found that the SDW gap anisotropy is isostructural to the superconducting gap anisotropy regarding to the angular dependence, gap minima locations, and relative gap magnitudes. Our results indicate that the superconducting pairing interaction and magnetic interaction share the same origin. The intra-orbital scattering plays an important role in constructing these interactions resulting in the orbital-selective magnetism and superconductivity in iron-based superconductors.

5 pages, 4 figures, See Supplemental Material at http://link.aps.org/supplemental/10.1103/PhysRevLett.124.247002

References in corpus (8)

• High-temperature superconductivity in iron-based materials
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Spin fluctuations and superconductivity in a 3D tight-binding model for BaFe2As2
• Spin reorientation in Na-doped BaFe${}_2$As${}_2$ studied by neutron diffraction
• Orbital-weight redistribution triggered by spin order in the pnictides

Cited by in corpus (1)

• Short-range nematic fluctuations in Sr1-xNaxFe2As2 superconductors