Scaling of the vortex-liquid resistivity in optimally doped and oxygen-deficient YBa2Cu3O7-δ single crystals -: art. no. 184511

The consequences of a recently proposed model [A. Rydh. O. Rapp. and M. Andersson. Phys. Rev. Lett. 83. 1850 (1999)] for the vortex-liquid resistivity close to a vortex liquid-to-glass transition are anal-zed in detail. We find a detailed quantitative agreement between the model and resistivity measurements on disordered, optimally doped YBa2Cu3O7-delta single crystals. For temperatures below the superconducting transition temperature. a scaling of all measured resistivity curves in magnetic field (0<B<less than or equal to>12 T) is obtained. Possible ways of slightly modifying the model in order to fully describe resistivity measurements on more anisotropic underdoped oxygen-deficient YBa2Cu3O7-delta single crystals are suggested. The physical interpretation of the model and its connection to other models of the vortex-liquid resistivity are discussed. in particular, we find close connections to vortex glass models and to a generalized Coulomb gas model.