Hugues Pothier (SPEC, CEA Saclay) - Jeudi 21 novembre.
Superconductors are characterized by a dissipationless current. Since the work of
Josephson 50 years ago, it is known that a supercurrent can even flow through
tunnel junctions between superconductors. This Josephson effect also occurs
through any type of "weak links" between superconductors : non-superconducting
materials, constrictions, ... A unified understanding of the Josephson effect has
emerged from a mesoscopic description of weak links. It predicts in particular that
the sign of the Josephson supercurrent can be reversed. I will present experiments
performed on the simplest conductor possible, a single-atom contact between
superconductors, that illustrate these concepts.
You can also watch this video on the multimedia site ENS :savoirs.ens.fr