Superconductivity in a single layer alkali-doped FeSe: a weakly coupled two-leg ladder system

Abstract

We prepare single layer potassium-doped iron selenide (110) film by molecular beam expitaxy. Such a single layer film can be viewed as a two-dimensional system composed of weakly coupled two-leg iron ladders. Scanning tunneling spectroscopy reveals that superconductivity is developed in this two-leg ladder system. The superconducting gap is similar to that of the multi-layer films. However, the Fermi surface topology given by first-principles calculation is remarkably different from that of the bulk materials. Our results suggest that superconducting pairing is very short-ranged or takes place rather locally in iron-chalcogenides. The superconductivity is most likely driven by electron-electron correlation effect and is insensitive to the change of Fermi surfaces.

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Cited by in corpus (2)

• Ab initio downfolding study of the iron-based ladder superconductor BaFe${}_2$S${}_3$
• Electronic Structure Reconstruction across the Antiferromagnetic Transition in TaFe${}_{1.23}$Te${}_3$ Spin Ladder