Angular field-dependent dimensional transition in YBa2Cu3O7/PrBa2Cu3O7 superlattice

Abstract

We report for the first time on the angular magnetic field dependence of the activation energy U0 of flux motion in YBa2Cu3O7/PrBa2Cu3O7 superlattice. We find that the U0 changes from 2D behavior to 3D behavior when the field component perpendicular to the ab-plane Hsin θ is larger than the crossover field. This dimensional crossover is discussed in terms of entanglement of the vortices, and our estimated entanglement field agrees excellently with the observed crossover field. We also find that the perpendicular field component plays a key role in the dimensional transition.