Hc2 of anisotropy two-band superconductors by Ginzburg-Landau approach

The purpose of this research is to study the upper critical field Hc2 of two-band superconductors by two-band Ginzburg-Landau approach. The analytical formula of Hc2 included anisotropy of order parameter and anisotropy of effective-mass are found. The parameters of the upper critical field in ab-plane (Hc2∥ab) and c-axis (Hc2∥c) can be found by fitting to the experimental data. Finally, we can find the ratio of upper critical field that temperature dependent in the range of experimental result.