“Giant” Josephson proximity effect

Abstract

The “giant” Josephson current through the superconductor–normal–superconductor (S–N′–S) junction where the barrier N′ is an underdoped cuprate is explained. The thickness of N′ greatly exceeds the coherence length. The origin of this phenomenon is related to the origin of the metallic pseudogap state. The ability of a giant barrier to transfer a Josephson current is due to the inhomogeneous nature of the barrier and the presence of the superconducting “islands” embedded in the normal metallic matrix.