Magnetic quantization and the upper critical field of superconductors

Recently, there has been renewed interest in the effect of orbital quantization on the upper critical field of superconductors, given the possibility of reentrant behavior at high fields. In this paper, the Gor'kov equations are solved numerically in the limit where only a few Landau levels are involved, including the effects of impurities and a nonzero g factor, for a set of parameters appropriate to a low-carrier-density superconductor. It is shown that these effects conspire to make the experimental observation of this effect possible, but unlikely