ABSTRACT

That superconductivity is a macroscopic quantum phenomenon is undoubtedly the main message to be drawn from the previous introductory chapter. There we saw that flux quantisation is a remarkable demonstration of the strange behaviour exhibited by macroscopic systems which are governed by fundamental quantum laws. In this chapter we introduce the Josephson effects, the second piece of fundamental physics which has been exploited in the development of superconducting electronics. If anything they provide an even clearer view of the quantum nature of superconductivity, through a decidedly esoteric mix of properties.