Abstract
We present a quantitative analysis of finite frequency fluctuation conductivity above and below in cuprate superconductors in zero dc magnetic field. In a crystal showing a linear in temperature increase of the penetration depth at low temperatures, we find that two-dimensional (2D) finite frequency Gaussian conductivity fluctuations above cross over into a slower divergence of the conductivity as is approached from above. We find that the critical regime above is less than about 0.6 K wide. At and below , 3D fluctuations dominate the conductivity, with evidence of 3D XY critical scaling of the imaginary part of the conductivity down to 5 K below . © 1996 The American Physical Society.
- Received 5 October 1995
DOI:https://doi.org/10.1103/PhysRevB.53.2792
©1996 American Physical Society