Electron-Phonon interaction in hexagonal layered compounds

The discovery of superconductivity in MgB$_2$ has initiated a thorough search for new electron-phonon ($e-ph$) superconductors, particulary among hexagonal layered compounds. In this talk I will describe, using {\em ab-initio} methods, the factors that determine the electron-phonon properties of two classes of recently discovered superconductors, namely alkali-earth intercalated graphites (highest T$_c$ 15.1 K for CaC$_6$)[1] and metal-intercalated ternary compounds MaAlSi. [2] \newline References: \newline [1] J. S. Kim, L. Boeri, R. K. Kremer, and F. S. Razavi Phys. Rev. B 74, 214513 (2006), Phys. Rev. Lett. 96, 217002 (2006), and Phys. Rev. Lett. 027001 (2007). \newline L. Boeri, G.B. Bachelet, M. Giantomassi, O.K. Andersen, Phys. Rev. B 76, 064510 (2007). \newline [2] M. Giantomassi, L. Boeri, and G. B. Bachelet, Phys. Rev. B 72, 224512 (2005)