Masses and phase structure in the Ginzburg-Landau model

Abstract

We study numerically the phase structure of the Ginzburg-Landau model, with particular emphasis on mass measurements. There is no local gauge-invariant order parameter, but we find that there is a phase transition characterized by a vanishing photon mass. For type-I superconductors the transition is of first order. For type-II, a first-order transition is excluded by susceptibility analysis, but the photon correlation length is compatible with second-order critical behavior with $\ensuremath{\nu}\ensuremath{\sim}$$\frac{1}{2}$. The scalar mass, in contrast, does not show clear critical behavior in the type-II regime for $\stackrel{\ensuremath{\rightarrow}}{V}\ensuremath{\infty}$, contrary to the conventional picture.