title: Superconductivity in doped sp3 semiconductors: the case of the clathrates.
abstract: We present a joint experimental and theoretical study of the superconductivity in doped silicon clathrates. The critical temperature in Ba(8)@Si-46 is shown to strongly decrease with applied pressure. These results are corroborated by ab initio calculations using MacMillan's formulation of the BCS theory with the electron-phonon coupling constant lambda calculated from perturbative density functional theory. Further, the study of I(8)@Si-46 and of gedanken pure silicon diamond and clathrate phases doped within a rigid-band approach show that the superconductivity is an intrinsic property of the sp(3) silicon network. As a consequence, carbon clathrates are predicted to yield large critical temperatures with an effective electron-phonon interaction much larger than in C60.
authors.affiliation: LPMCN, Université Claude Bernard Lyon I and CNRS, UMR 5586, Bâtiment Brillouin, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
authors.forename: D
authors.initials: D
authors.lastname: Connétable
authors.forename: V
authors.initials: V
authors.lastname: Timoshevskii
authors.forename: B
authors.initials: B
authors.lastname: Masenelli
authors.forename: J
authors.initials: J
authors.lastname: Beille
authors.forename: J
authors.initials: J
authors.lastname: Marcus
authors.forename: B
authors.initials: B
authors.lastname: Barbara
authors.forename: A M
authors.initials: AM
authors.lastname: Saitta
authors.forename: G-M
authors.initials: GM
authors.lastname: Rignanese
authors.forename: P
authors.initials: P
authors.lastname: Mélinon
authors.forename: S
authors.initials: S
authors.lastname: Yamanaka
authors.forename: X
authors.initials: X
authors.lastname: Blase