Superconductivity in doped cubic silicon: An ab initio study

The authors study within a first-principles approach the band structure, vibrational modes, and electron-phonon coupling in boron-, aluminum-, and phosphorus-doped silicon in the diamond phase. Their results provide evidences that the recently discovered superconducting transition in boron-doped cubic silicon, with a transition temperature of ∼0.34K, can be explained within a standard phonon-mediated mechanism. The importance of lattice compression and dopant related stretching modes are emphasized. The authors find that TC can be increased by one order of magnitude by adopting aluminum doping instead of boron.