Quantum interference in a high-transition-temperature superconductor based on nanoslits on SrTiO₃ substrate

The Josephson junction, a key component of superconducting quantum circuits, is much less mature, especially for the high-transition (high-T_c) temperature cuprate superconductors. Herein, we report on the realization of high-T_c Josephson junction based on nanoslits on a SrTiO₃ substrate. We demonstrate the ability to manipulate the current-voltage characteristics of YBa₂Cu₃O_7−x bridges continuously from superconducting current-dominated to Josephson junction behavior by changing the irradiation parameters of the focused Ga⁺ ion beam on a single-crystal SrTiO₃ substrate. The periodic critical current that depends on the magnetic flux coupled into the superconducting quantum interference devices was observed, which exactly reflects the effects of quantum tunneling and flux quantization. To some extent, this weak link within the framework of the semiconductor manufacturing process shows the potential to provide a cost-effective, highly efficient, and reliable pathway for scaling up quantum mechanical superconducting circuits, which is promising for the fabrication process.