"Fate of the Josephson Effect in Thin-film Superconductors"Gil Refael , Caltech [Host: Victor Galitski]
ABSTRACT:
The dc Josephson effect is a probe of the fundamental nature
of the superconducting state. In this talk, I will analyze the case of
two superconducting thin films connected by a point contact. Remarkably,
the Josephson effect is absent at nonzero temperature, even below the
K-T transition of the films, and the resistance across the contact is
nonzero. Moreover, the point contact resistance is found to vary with temperature in a nearly activated fashion, with a universal energy
barrier determined only by the superfluid stiffness characterizing the
films, an angle characterizing the geometry, and whether or not the
Coulomb interaction between Cooper pairs is screened. As will be shown,
this should be testable even in finite systems at a proper range of
length-scales and temperatures.
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Condensed Matter Seminar Thursday, March 30, 2006 4:00 PM Physics Building, Room 204 Note special time. Note special room. |
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