https://doi.org/10.1140/epjb/e2003-00166-7
Gaussian Effective Potential and superconductivity
1
Dipartimento di Fisica e Astronomia, Università di
Catania, Via S. Sofia, 64, 95123 Catania, Italy
2
Istituto Nazionale per la Fisica della Materia, UdR Catania, Italy
3
Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Italy
Corresponding author: a giuseppe.angilella@ct.infn.it
Received:
18
November
2002
Revised:
26
March
2003
Published online:
20
June
2003
The Gaussian Effective Potential in a fixed transverse unitarity gauge is studied for the static three-dimensional U(1) scalar electrodynamics (Ginzburg-Landau phenomenological theory of superconductivity). In the broken-symmetry phase the mass of the electromagnetic field (inverse penetration depth) and the mass of the scalar field (inverse correlation length) are both determined by solution of the coupled variational equations. At variance with previous calculations, the choice of a fixed unitarity gauge prevents from the occurrence of any unphysical degree of freedom. The theory provides a nice interpolation of the experimental data when approaching the critical region, where the standard mean-field method is doomed to failure.
PACS: 74.40.+k – Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.) / 11.15.Ex – Spontaneous breaking of gauge symmetries / 74.20.De – Phenomenological theories (two-fluid, Ginzburg-Landau, etc.) / 11.15.Tk – Other nonperturbative techniques
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003
