1 research outputs found
Anomalous Behavior of the Upper Critical Field in Extreme Type-II Superconductors at Low Temperatures
We present a detailed numerical calculation of the upper critical field
for a bulk extreme type-II superconductor. Particular emphasis is
placed on the high-field, low-temperature regime of the HT-phase diagram. In
this regime it is necessary to go beyond the standard semi-classical theory and
include the effects of Landau quantization of the electronic motion on the
superconducting state. The presence of Landau level quantization induces an
upward curvature in at of for those
superconducting systems in which the slope of at is 0.2 Tesla/Kelvin. We construct a simple analytical model that can account for
this behavior based on the renormalization of the BCS coupling constant by the
off-diagonal pairing of electrons on Landau levels.Comment: 13 pages, Revtex, 3 ps figures, to appear in Physica