Ames Laboratory; Chemistry; Physics and Astronomy
Chemistry, Physics and Astronomy, Ames Laboratory
Physical Review Letters
Two ordering states, antiferromagnetism and nematicity, have been observed in most iron-based superconductors (SCs). In contrast to those SCs, the newly discovered SC CaK(Fe1−xNix)4As4exhibits an antiferromagnetic (AFM) state, called hedgehog spin-vortex crystal (SVC) structure, without nematic order, providing the opportunity for the investigation into the relationship between spin fluctuations and SC without any effects of nematic fluctuations. Our 75As nuclear magnetic resonance studies on CaK(Fe1−xNix)4As4 (0≤x≤0.049) revealed that CaKFe4As4 is located close to a hidden hedgehog SVC AFM quantum-critical point (QCP). The magnetic QCP without nematicity in CaK(Fe1−xNix)4As4 highlights the close connection of spin fluctuations and superconductivity in iron-based SCs. The advantage of stoichiometric composition also makes CaKFe4As4 an ideal platform for further detailed investigation of the relationship between magnetic QCP and superconductivity in iron-based SCs without disorder effects.
DOE Contract Number(s)
Department of Energy Subject Categories
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
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