Disorder version of the Abelian Higgs model and the order of the superconductive phase transition

Summary

We transform the Abelian Higgs model in three dimensions (i.e. the Grinzburg-Landau theory) to a disorder field theory. The new fields describe the grand canonical ensemble of vortex lines in the superconductor and take a nonzero expectation in the normal state (signalizing their proliferation). The disorder theory allows for a simple determination of the tricritical point where the second-order phase transition changes to first. This happens for a Grinzburg-Landau parameter (= ratio of penetration depth to coherence length)K 0.8/√2.