The theory for an array of Josephson coupled superconductors is formulated in terms of temperature-ordered Feynman diagrams. The individual grains have an unperturbed ground state with a fixed number of electrons rather than a fixed phase. The formulation is illustrated by calculating the free energy. With relevant approximations this justifies the frequently used planar rotator model and the Giovannini-Weiss form for the free energy.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)
- Metals and Alloys