Anomalous Behavior of the Upper Critical Field in Extreme Type-II Superconductors at Low Temperatures

Abstract

We present a detailed numerical calculation of the upper critical field $H_{c2}(T)$ 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 $H_{c2}(T)$ at $\sim 10$ of $T_{c0}$ for those superconducting systems in which the slope of $H_{c2}(T)$ at $T_{c0}$ is $\ge$ 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.

13 pages, Revtex, 3 ps figures, to appear in Physica C

References in corpus (1)

• Density of states of a type-II superconductor in a high magnetic field: Impurity effects

Cited by in corpus (3)

• Quasiparticle Thermal Conductivities in a Type-II Superconductor at High Magnetic Field
• Low-Temperature Specific Heat of an Extreme-Type-II Superconductor at High Magnetic Fields
• Spin paramagnetism in d-wave superconductors