Screening-Approximation Prediction of Peaking in the Specific Heat of a Superconducting Film

Abstract

All contributions to the free energy of $O\left(n\right)\mathrm{}$ and of $O\left(1\right)\mathrm{}$ are computed for an $n$-component two-dimensional Ginzburg-Landau field. The $O\left(1\right)\mathrm{}$ terms correspond to ring diagrams, and their sum constitutes the first-order screening approximation. The second derivative of the free energy with respect to temperature yields a predicted specific heat for $n=2\mathrm{}$ which peaks, in qualitative disagreement with the monotonic temperature variation found experimentally for a superconducting film by Zally and Mochel.