American Journal of Physics

Functional integrals and the BCS theory of superconductivity

G. Fletcher

Published Jan 1, 1990• 12 citations

Abstract

As an example of the application of functional integral techniques to condensed matter physics, the partition function for the BCS model for superconductivity is derived. The pairing term in the Hamiltonian is linearized by applying the Hubbard–Stratonovich transformation. It is shown that the standard result for the gap equation can be obtained by making a saddle-point approximation to the functional integral.

DOI: 10.1119/1.16318

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