Theoretical study of superconductivity in highly condensed Si

We present a review of the theoretical calculations of the electron-phonon interactions in three highly condensed phases of Si:β-Sn, simple hexagonal (sh) and hexagonal close packed (hcp). A pseudopotential method is used to calculate the phonon frequency, the phonon linewidth and the electron-phonon coupling constant. The pressure dependence of these variables is also discussed. The superconducting transition temperature is estimated to be higher than 10 K for both the sh and hcp phases near the phase transition from sh to hcp. (orig.)