Scaling properties of the anisotropic magnetoresistance in YBa2Cu3O7PrBa2Cu3O7 superlattices

We report on measurements of the magnetoresistance as a function of the angle θ between magnetic field H and the basal plane in YBa2Cu3O7/PrBa2Cu3O7 superlattices with two different thicknesses of the separator layer (YBCO:PrBCO=1:1 and 1:3). The angular dependence of the magnetoresistance for different field intensities can be scaled into a single curve by introducing the reduced field,with the anisotropy paramete γ. In the YBCO/PrBCO=1:3 superlattice, quite good scaling is achieved with only the perpendicular field component, which implies fully decoupled YBCO layers (γ=∞). In the YBCO/PrBCO=1:1 superlattice, however, a finite anisotropy (γ≈50) is necessary to obtain a convincing scaling. Measurements of the magnetoresistance for different directions between magnetic field and transport current in these superlattices have shown that the resistive transition broadening in the field is independent of the macroscopic Lorentz force. An interpretation of these data based on the two-dimensional fluctuation model is also presented