The chiral p-wave order parameter in Sr₂RuO₄ would make it a special case amongst the unconventional superconductors. A consequence of this symmetry is the possible existence of superconducting domains of opposite chirality. At the boundary of such domains, the locally suppressed condensate can produce an intrinsic Josephson junction. Here, we provide evidence of such junctions using mesoscopic rings, structured from Sr₂RuO₄ single crystals. Our order parameter simulations predict such rings to host stable domain walls across their arms. This is verified with transport experiments on loops, with a sharp transition at 1.5 K, which show distinct critical current oscillations with periodicity corresponding to the flux quantum. In contrast, loops with broadened transitions at around 3 K are void of such junctions and show standard Little–Parks oscillations. Our analysis demonstrates the junctions are of intrinsic origin and makes a compelling case for the existence of superconducting domains.

Sr ₂ RuO _4中的手性p波阶参数将使其成为非常规超导体中的特例。这种对称性的结果是可能存在相反手性的超导域。在这些区域的边界处，局部抑制的凝结水可以产生本征约瑟夫森结。在这里，我们提供了使用由Sr ₂ RuO ₄构成的介观环进行此类连接的证据单晶。我们的阶数参数模拟预测此类环将在其臂上承载稳定的畴壁。这在环路上进行了传输实验，在1.5 K处有一个急剧的跃迁，这证明了明显的临界电流振荡，其周期性对应于通量量子。相比之下，在3 K左右具有宽跃迁的环没有这种结，并显示标准的Little-Parks振荡。我们的分析表明，结是内在起源的，并为超导域的存在提供了令人信服的理由。