Disappearance of Bose-glass behavior in transport properties of YBa2Cu3Oy films with columnar defects

The glass transitions of the vortex system in Au-ion irradiated YBa2Cu3Oy films have been studied by the measurements of transport properties as a function of magnetic field B and angle 0 of B to the direction of columnar defects. At theta = 0degrees, we find an anomalous upturn behavior of the glass transition line B-g (T) at B similar to B-phi/3, where B-phi is the matching field. In B > B-phi/3, the theta dependence of glass transition temperature T-g reveals cusp-like behavior with a peak at theta = 0degrees, which is consistent with the Bose glass theory. In B < B-phi/3, on the other hand, T-g is almost independent of theta, suggesting the system undergoes the vortex glass transition induced by the inherent point-like defects.