Superconductivity at the two-dimensional limit.
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.
Qin
Shengyong
S
Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
Kim
Jungdae
J
Niu
Qian
Q
Shih
Chih-Kang
CK