Forced Entanglement vs Anisotropic Dissipation in a Vortex Line Liquid
Abstract
We present evidence for forced topological entanglement of line-like vortices in the liquid regime of YBa2Cu3O7-δ with columnar defects. By splaying the defects within a fixed plane (in-fan) we create a c^-axis phase coherent vortex (string) structure which correlates with anisotropic dissipation. The high-field vortex motion is ``easy'' in fan and ``hard'' across fan in crystals-a signature of forced entanglement by a small angle splay. The high-field anisotropy is surprisingly reversed in thin films, where forced entanglement is absent.
- Publication:
-
Physical Review Letters
- Pub Date:
- November 1997
- DOI:
- 10.1103/PhysRevLett.79.4258
- Bibcode:
- 1997PhRvL..79.4258L