Ginzburg-Landau theory of two-band superconductors: Absence of type-1.5 superconductivity

It is shown that within the Ginzburg-Landau (GL) approximation the order parameters Delta(1)(r, T) and Delta(2)(r, T) in two-band superconductors vary on the same length scale, the difference in zero-T coherence lengths xi(0v) similar to hv(Fv)/Delta(v)(0), v = 1,2 notwithstanding. This amounts to a single physical GL parameter kappa and the classic GL dichotomy: kappa < 1/root 2 for type I and kappa > 1/root 2 for type II.