When superconductivity does not fear magnetism: Insight into electronic structure of RbEuFe${}_4$As${}_4$

Abstract

In the novel stoichiometric iron-based material RbEuFe${}_4$As${}_4$ superconductivity coexists with a peculiar long-range magnetic order of Eu 4f states. Using angle-resolved photoemission spectroscopy, we reveal a complex three dimensional electronic structure and compare it with density functional theory calculations. Multiple superconducting gaps were measured on various sheets of the Fermi surface. High resolution resonant photoemission spectroscopy reveals magnetic order of the Eu 4f states deep into the superconducting phase. Both the absolute values and the anisotropy of the superconducting gaps are remarkably similar to the sibling compound without Eu, indicating that Eu magnetism does not affect the pairing of electrons. A complete decoupling between Fe- and Eu-derived states was established from their evolution with temperature, thus unambiguously demonstrating that superconducting and a long range magnetic orders exist independently from each other. The established electronic structure of RbEuFe${}_4$As${}_4$ opens opportunities for the future studies of the highly unorthodox electron pairing and phase competition in this family of iron-based superconductors with doping.

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Cited by in corpus (7)

• Smectic Pair Density Wave Order in EuRbFe4As4
• Aspects of topological superconductivity in 2D systems: noncollinear magnetism, skyrmions, and higher-order topology
• Novel magnetic stoichiometric superconductor EuRbFe4As4
• Antiferromagnetic resonances in twinned EuFe2As2 single crystal
• The Type-II/Type-I Crossover in Dirty Ferromagnetic Superconductors
• Evolution from helical to collinear ferromagnetic order of the Eu${}^{2+}$ spins in RbEu(Fe${}_{1-x}$Ni${}_x$)${}_4$As${}_4$
• Vortex matter and strong pinning in underdoped PrFeAs(O,F) with atomic-sized defects