Effects of columnar defects and intrinsic pinning on the Bose-glass transitions of YBa2Cu3O7 and Bi2Sr2CaCu2O8 thin films

We study the AC resistivity (3 mHz-50 MHz) in the ab-plane of YBa2Cu3O7 and Bi2Sr2CaCu2O8-films, c-axis grown on SrTiO3(001) and having almost identical zero-field performances. Searching for thermodynamic transitions to stable ''glassy'' superconductivity in the presence of magnetic fields H-vector, we observe a significant increase of the glass transitions Tg(H-vector) in YBa2Cu3O7 when changing the orientation from H-vector parallel c-vector to H-vector perpendicular to c-vector and also after creation of columnar defects parallel to c-vector (matching field Hφ=10 kOe) for H≤Hφ. In the strongly anisotropic Bi2Sr2CaCu2O8, on the other hand, which exhibits non-superconducting TAFF-behavior in the pristine state, columnar defects (Hφ=10 kOe) produce transitions to Bose-glass (BG) superconductivity in fields H-vector parallel c-vector up to Hφ. Surprisingly, the columnar defects parallel to c-vector raise the transition temperatures Tg(H), also for H-vector perpendicular to c-vector. (orig.)