Nonreciprocal critical current in an obliquely ion-irradiated YBa2Cu3O7 film

We observed a superconducting diode effect (SDE) at 77K in a YBa2Cu3O7 (YBCO) film irradiated with 75-MeV-Au ions directed 30 degrees-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.

Automated summary

We observed a superconducting diode effect (SDE) in a YBa2Cu3O7 (YBCO) film irradiated with 75-MeV-Au ions at 77K under an incident angle of 30 degrees-off normal to the film surface. The dc critical current showed up to 3% asymmetry in out-of-plane magnetic fields. This unconventional SDE in YBCO films is attributed to the asymmetric barrier between the film surface and the film-substrate interface, which affects the entry of vortices. We also observed a sudden reversal of the diode polarity when the magnetic field angle was rotated across the ion-incident angle.