Anomalous behavior of superconducting-normal mesoscopic structures near T(c)
We observe a maximum in the conductance of Al/n-GaAs junctions at temperatures 20 mK lower than the superconducting transition temperature (T(c)). This is the first observation of a peak in the conductance near the superconducting transition in superconducting-normal (S/N) junctions. To accommodate this effect we calculate the full temperature dependence of the conductance of these structures, invoking quasiclassical Green's functions in the diffusive limit. In addition to the well-known low-temperature peak at temperatures on the order of the Thouless energy, we find a maximum near T(c). This peak has the same origin as the subgap conductance observed in S/N junctions at low temperatures.
Shapira
S
Cavendish Laboratory, University of Cambridge, Madingley Road CB3 0HE, United Kingdom.
Linfield
EH
Lambert
CJ
Seviour
R
Volkov
AF
Zaitsev
AV