Phys.org  October 23, 2023
Metallic ferromagnets with strongly interacting electrons often exhibit remarkable electronic phases such as ferromagnetic superconductivity, complex spin textures, and nontrivial topology. A team of researchers in the US (UC Berkeley, Los Alamos National Laboratory) conducted a series of experiments with a new type of layered 2D metal, finding connections in electronic behavior that might potentially be useful for fabricating complex superconducting quantum processors. They discussed the synthesis of a layered magnetic metal NiTa4Se8 (or Ni1/4TaSe2) with a Curie temperature of 58 Kelvin. Magnetization data and density functional theory calculations indicated that the nickel atoms host uniaxial ferromagnetic order of about 0.7μB per atom, while an even smaller moment is generated in the itinerant tantalum conduction electrons. Strong correlations were evident in flat bands near the Fermi level, a high heat capacity coefficient, and a high Kadowaki-Woods ratio. Density functional theory calculations suggested that electron and hole Fermi surfaces in the ferromagnetic phase were associated with opposite spin polarization. When the system was diluted with magnetic ions, the samples became superconducting below about 2 Kelvin. The researchers also discussed possible mechanisms for superconductivity in this family… read more. TECHNICAL ARTICLEÂ
Electronic structure measurements and calculations… Credit: Phys. Rev. B 106, 224429, 29 December 2022