Abstract
For the 40 K superconductor we have calculated the electronic and phononic structures and the electron-phonon (e-ph) interaction throughout the Brillouin zone ab initio. In contrast to the isoelectronic graphite, has holes in the bonding σ bands, which contribute to the density of states: The total interaction strength, and is dominated by the coupling of the σ holes to the bond-stretching optical phonons with wave numbers in a narrow range around Like the holes, these phonons are quasi-two-dimensional and have wave vectors close to where their symmetry is E. The π electrons contribute merely 0.25 to λ and to With Eliashberg theory we evaluate the normal-state resistivity, the density of states in the superconductor, and the B-isotope effect on and and find excellent agreement with experiments, when available. is reproduced with and thus seems to be an intermediate-coupling e-ph pairing s-wave superconductor.
- Received 20 March 2001
DOI:https://doi.org/10.1103/PhysRevB.64.020501
©2001 American Physical Society