Microscopic quantum interference in the theory of superconductivity

It is an honor and a pleasure to speak to you today about the theory of superconductivity. In a short lecture one can no more than touch on the long history of experimental and theoretical work on this subject before 1957. Nor can one hope to give an adequate account of how our understanding of superconductivity has evolved since that time. The theory we presented in 1957, applied to uniform materials in the weak‐coupling limit so defining an ideal superconductor, has been extended in almost every imaginable direction. To these developments so many authors have contributed that we can make no pretense of doing them justice. I will confine myself here to an outline of some of the main features of our 1957 theory, an indication of directions taken since and a discussion of quantum interference effects due to the single‐spin pairing in superconductors which might be considered the microscopic analogue of the effects discussed by Professor Schrieffer.