Gauge dependenceof the order parameter anomalous dimension in the Ginzburg-Landau model and the critical fluctuations in superconductors

Abstract

The critical fluctuations of superconductors are discussed in a fixed dimension scaling suited to describe the type II regime. The gauge dependence of the anomalous dimension of the scalar field is stablished exactly from the Ward-Takahashi identities. Its fixed point value gives the $\eta$ critical exponent and it is shown that $\eta$ is gauge independent, as expected on physical grounds. In the scaling considered, $\eta$ is found to be zero at 1-loop order, while $\nu \approx 0.63$. This result is just the 1-loop values for the XY model obtained in the fixed dimension renormalization group approach. It is shown that this XY behavior holds at all orders. The result $\eta ={\eta }_{XY}$ should be contrasted with the negative values frequently reported in the literature.

EuroLaTex, 7 pages, 2 figures, reference updated; version to be published in Europhysics Letters

References in corpus (4)

• Critical Behavior of the Meissner Transition in the Lattice London Superconductor
• Three-dimensional U(1) gauge+Higgs theory as an effective theory for finite temperature phase transitions
• Critical properties of the topological Ginzburg-Landau model
• A note on the phase transition in a topologically massive Ginzburg-Landau theory

Cited by in corpus (6)

• Charged fixed point in the Ginzburg-Landau superconductor and the role of the Ginzburg parameter $\kappa$
• Scaling critical behavior of superconductors at zero magnetic field
• Anomalous dimensions and phase transitions in superconductors
• Three-Loop Ground-State Energy of O(N)-Symmetric Ginzburg-Landau Theory Above T_c in 4-epsilon Dimensions with Minimal Subtraction
• Anomalous Dimension of Dirac's Gauge-Invariant Nonlocal Order Parameter in Ginzburg-Landau Field Theory
• The superconducting phase transition and gauge dependence