Gaussian Effective Potential for the U(1) Model of Superconductivity

(with G.G.N. Angilella, R. Pucci, F. Siringo)

Massimo Camarda


Abstract
The Gaussian Effective Potential[1,2] in a fixed transverse unitarity gauge is studied for the three-dimensional U(1) model of superconductivity (Ginzburg-Landau phenomenological theory). In the broken-symmetry phase the mass of the elettromagnetic field (inverse penetration depth) and themass of the scalar field (inverse correlation length) are both determined by solution of the coupled variational equations. At variance with previous calculations [2] the choice of a fixed unitarity gauge prevents from the occurrence of any unphysical degree of freedom. The theory provides a nice fit of the experimental data [3] when approaching the critical region where the standard mean-field method is doomed to failure.

[1] P.M.Stevenson, Phys.Rev. D32, 1389 (1985).
[2] R. Ibanez-Meier, I.Stancu, P.M.Stevenson, Z.Phys. C70, 307 (1996).
[3] G. Brandstatter et al. Physica C235-240, 1845 (1994).

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Elenco dei partecipanti al convegno di Bari.

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