Abstract
The organic superconductor (with ) possesses a number of puzzling electronic properties, including the temperature dependence of resistivity, magnetic susceptibility, and Hall coefficient. To provide a basis for understanding these properties, we carried out band calculations using the two-dimensional Hubbard model with the unrestricted-Hartree-Fock theory. The electron transfer hopping interactions are from ab initio calculations. For a Hubbard parameter of the calculated results give good agreement with Shubnikov-de Haas and magnetic breakdown experiments. The calculations lead to a two-band semimetal with a momentum gap separating the electron and hole bands. The anomalous experimental observations are explained in terms of BEDT-TTF related phonons coupling these two bands. These results also provide a framework for describing the conduction properties of similar BEDT-TTF crystals. This approach should also be useful for other organic conductors.
- Received 7 April 1997
DOI:https://doi.org/10.1103/PhysRevB.56.11907
©1997 American Physical Society