Electronic structure of superconducting gallium‐doped germanium from ab‐initio calculations

Abstract

AbstractUsing ab‐initio calculations, we study the electronic structure of gallium‐doped germanium, which was found recently to be a superconductor, with a critical temperature of 0.5 K, and a particularly low density of Cooper pairs. The calculations of the electronic properties reveal that no sign of an impurity band is observed, and that the Fermi level lies in the valence band of Ge. Moreover, the calculation of the phonon frequencies shows that a new mode associated to the Ga atom is appearing, around 175 cm–1. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)