COLUMNAR-DEFECT-INDUCED RESISTIVITY MINIMA AND BOSE GLASS SCALING OF LINEAR DISSIPATION IN TL2BA2CACU2O8 EPITAXIAL-FILMS

The angular dependence of the flux flow resistivity rho(THETA,T,H) in T12Ba2CaCU2O8 is measured as the external field is brought into alignm ent with heavy-ion-irradiation-induced columnar defects. A flux lock-i n state, manifested as a minimum in the rho(THETA,T,H) data, evolves a s the system is cooled deeper into the mixed state. This observation p rovides compelling evidence for nonzero line tension of vortices in th is highly anisotropic superconductor. The temperature dependence of th e flux flow resistivity at perfect alignment is consistent with Bose g lass theory of vortex localization at columnar defects.