Enhanced Josephson tunneling between high-temperature superconductors through a normal pseudogap underdoped cuprate with a finite-energy cooperon

The Josephson coupling between optimally cuprate superconductors separated by a spacer with a finite energy cooperon excitation which contributes to the Josephson coupling strength, is examined. For an underdoped cuprate barrier in its normal state, the YRZ model gives a good description of the temperature dependent enhanced Josephson coupling. A detailed examination of origin of the enhancement shows a significant contribution from the cooperon excitation which is comparable to that from nodal quasiparticles.
Comment: 5 pages, 4 figures