Flow of electric current between two pieces of superconducting material (see superconductivity ) separated by a thin layer of insulating material.
This flow was predicted by the British physicist Brian Josephson in 1962, based on the BCS theory (see John Bardeen ). According to Josephson, pairs of electron s can move from one superconductor to the other across the insulating layer (tunneling). The locus of this action is called a Josephson junction. The Josephson current flows only if no battery is connected across the two conductors. A major application of this discovery is in superfast switching devices used in computers, which can be 100 times faster than ordinary semiconducting circuits.