Hybridization between K and C₆₀ Electronic States in Superconducting K₃Ba₃C₆₀

Abstract

We have studied the electronic structure of the superconducting fulleride K₃Ba₃C₆₀ using the local density approximation in the density functional theory. We have found the presence of the hybridization not only between Ba and C₆₀ states but also between K and C_{60 states. This novel hybridization should have an effect on the electronic properties, including superconductivity. Also in Rb3Ba3C60, the hybridization between Rb and C60 is found as well. In addition, the density of states at Fermi level of K3Ba3C60 is found to be slightly larger than that of Rb3Ba3C60, although the lattice constant of K3Ba3C60 is shorter than that of Rb3}Ba₃3₆₀. These results are in sharp contrast to A₃C₆₀ superconductors (A=alkali-metal atoms).

Key Words:

• Electronic structure
• K₃Ba₃C₆₀
• Rb₃Ba₃3₆₀
• superconductivity
• Density-Functional Theory