title: Superconductivity at the two-dimensional limit.
abstract: Superconductivity in the extreme two-dimensional limit is studied on ultrathin lead films down to two atomic layers, where only a single channel of quantum well states exists. Scanning tunneling spectroscopy reveals that local superconducting order remains robust until two atomic layers, where the transition temperature abruptly plunges to a lower value, depending sensitively on the exact atomic structure of the film. Our result shows that Cooper pairs can still form in the last two-dimensional channel of electron states, although their binding is strongly affected by the substrate.
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Shengyong
authors.initials: S
authors.lastname: Qin
authors.forename: Jungdae
authors.initials: J
authors.lastname: Kim
authors.forename: Qian
authors.initials: Q
authors.lastname: Niu
authors.forename: Chih-Kang
authors.initials: CK
authors.lastname: Shih