Angular dependence of the zero resistance superconducting glass state in YBCO thin films

The authors present current versus voltage and resistivity data as a function of angle, magnetic field, and temperature. The critical scaling exponents extracted from the data are consistent with the new theories of the vortex and Bose glass. However, the angle dependence of the glass transition temperature is inconsistent with the vortex glass model and is explainable in a model utilizing both the vortex and Bose glass theories. The samples, high quality epitaxial thin films of YBCO, were also studied using the atomic force microscope and X-ray diffraction techniques. The effects of the microstructure on angle-dependent current versus voltage measurements within the vortex glass framework are discussed.<>