Observation of Double-Dome Superconductivity in Potassium-Doped FeSe Thin Films
Observation of Double-Dome Superconductivity in Potassium-Doped FeSe Thin Films
We report on the emergence of two disconnected superconducting domes in alkali-metal potassium- (K-)doped FeSe ultrathin films grown on graphitized SiC(0001). The superconductivity exhibits hypersensitivity to K dosage in the lower-Tc dome, whereas in the heavily electron-doped higher-Tc dome it becomes spatially homogeneous and robust against disorder, supportive of a …