Abstract
We report on the temperature dependence of the far-infrared conductivity of single crystals for E∥c. With decreasing temperature, the conductivity shows a transition from a Drude-like behavior to a pseudogap at 180 which grows deeper below 180 K without any abrupt changes at the superconducting transition at =80 K. In the superconducting state the formation of the superfluid condensate can be seen. We show that in a variety of high- superconductors the value of the London penetration depth for E∥c correlates with the conductivity along the c direction. With respect to this correlation we discuss the possibility of Josephson coupling between the layers.
- Received 16 May 1994
DOI:https://doi.org/10.1103/PhysRevB.50.3511
©1994 American Physical Society