Finding the static critical exponent in YBa2Cu3O7 using critical current density

We grew thin films of hole-doped cuprate YBa2Cu3O7 (YBCO) using optimized pulsed laser deposition and patterned them into a meander wire with conventional photolithography techniques. We examined the normal-superconducting phase transition of the thin films via a critical scaling analysis of voltage vs current isotherms, where each measurement is the average of many reverse-polarity measurements. We expect the superconducting phase transition to obey critical (3D-XY) theory near the critical temperature and obey mean-field theory further from the critical temperature. We show that critical current density can access both the critical regime and the mean-field regime in a single sample. We present our results on the static critical exponent in both regimes for YBCO.