Nonreciprocal critical current in an obliquely ion-irradiated YBa2Cu3O7 film

We observed a superconducting diode effect (SDE) at 77 K in a YBa2Cu3O7 (YBCO) film irradiated with 75-MeV-Au ions directed 30°-off normal to the film surface. Up to 3% asymmetry in dc critical-current appeared remarkably in out-of-plane magnetic fields. In this field orientation, a conventional SDE does not emerge due to an asymmetric barrier to vortex entry between the film surface and the film–substrate interface. We also observed a sudden reversal of the diode polarity when the magnetic-field-angle was rotated across the ion-incident-angle. Our results indicate an unconventional SDE in YBCO films that include tilted 1D defects.