Influence of a single defect on the conductance of a tunnel point contact between a normal metal and a superconductor

• Published in: Физика низких температур
• Date: 2008
• Main Authors: Avotina, Ye.S., Kolesnichenko, Yu.A., van Ruitenbeek, J.M.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2008
• Subjects: Электpонные свойства металлов и сплавов
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/117881
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Influence of a single defect on the conductance of a tunnel point contact between a normal metal and a superconductor / Ye.S. Avotina, Yu.A. Kolesnichenko, J.M. van Ruitenbeek // Физика низких температур. — 2008. — Т. 34, № 11. — С. 1184-1191. — Бібліогр.: 32 назв. — англ.

We have investigated theoretically the conductance of a normal–superconductor point contact in the tunnel
 limit and analyzed the quantum interference effects originating from the scattering of quasi-particles by
 point-like defects. Analytical expressions for the oscillatory dependence of the conductance on the position
 of the defect are obtained for the defect situated either in the normal metal, or in the superconductor. It is
 found that the amplitude of oscillations significantly increases when the applied bias approaches the gap energy
 of the superconductor. The spatial distribution of the order parameter near the surface in the presence of
 a defect is also obtained.