title: Superconducting state in a gallium-doped germanium layer at low temperatures.
abstract: We demonstrate that the third elemental group-IV semiconductor, germanium, exhibits superconductivity at ambient pressure. Using advanced doping and annealing techniques of state-of-the-art semiconductor processing, we have fabricated a highly Ga-doped Ge (GeratioGa) layer in near-intrinsic Ge. Depending on the detailed annealing conditions, we demonstrate that superconductivity can be generated and tailored in the doped semiconducting Ge host at temperatures as high as 0.5 K. Critical-field measurements reveal the quasi-two-dimensional character of superconductivity in the approximately 60 nm thick GeratioGa layer. The Cooper-pair density in GeratioGa appears to be exceptionally low.
authors.affiliation: Dresden High Magnetic Field Laboratory (HLD) and Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf (FZD), P.O. Box 51 01 19, D-01314 Dresden, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Herrmannsdörfer
authors.forename: V
authors.initials: V
authors.lastname: Heera
authors.forename: O
authors.initials: O
authors.lastname: Ignatchik
authors.forename: M
authors.initials: M
authors.lastname: Uhlarz
authors.forename: A
authors.initials: A
authors.lastname: Mücklich
authors.forename: M
authors.initials: M
authors.lastname: Posselt
authors.forename: H
authors.initials: H
authors.lastname: Reuther
authors.forename: B
authors.initials: B
authors.lastname: Schmidt
authors.forename: K-H
authors.initials: KH
authors.lastname: Heinig
authors.forename: W
authors.initials: W
authors.lastname: Skorupa
authors.forename: M
authors.initials: M
authors.lastname: Voelskow
authors.forename: C
authors.initials: C
authors.lastname: Wündisch
authors.forename: R
authors.initials: R
authors.lastname: Skrotzki
authors.forename: M
authors.initials: M
authors.lastname: Helm
authors.forename: J
authors.initials: J
authors.lastname: Wosnitza