Systematic study of Josephson plasma resonance in Bi2Sr2CaCu2O8+delta withcolumnar defects

We have examined microscopic vortex states in single-crystalline Bi2Sr2CaCu 2O8+delta With various doses of columnar defects by Josephson plasma resona nce measurements. The global angular dependence of the resonance held was f ound to obey an anisotropic 3D scaling law with a temperature-dependent ani sotropy parameter gamma(eff). The anisotropy parameter gamma(eff) drastical ly changes at the threshold temperature T*, which is independent of the irr adiation dose. This gives a unified and quantitative description of interla yer coupling in the vortex liquid state. (C) 2000 Elsevier Science B.V. All rights reserved.