SrTio$_3$ 기판 위에 제작된 YBa$_2Cu_3O_7$ 계단형 모서리 조셉슨 접합의 각도에 따른 임계전류 특성

Angle-dependent modulation of the critical current of YBa$_2Cu_3O_7$ step-edge Josephson junctions on SrTiO$_3$ substrate

We have fabricated $_2Cu_3O_7$ step-edge junctions with different step orientations and studied their transition properties. Steps with different orientations were prepared on the substrate. Josephson junctions were made on a single substrate with step orientations ranging from 0$^{\circ}$ to 165$^{\circ}$ at 15$^{\circ}$ interval. We measured current-voltage characteristics, the critical current, and the superconducting transition temperature as a function of the angle. The critical current showed a modulation that has a maximum near 0$^{\circ}$ or 90$^{\circ}$ and a minimum near 45$^{\circ}$ and 135$^{\circ}$. We believe that the critical current modulation with the step orientation could be associated with the symmetry of high T$_c$ superconductor.