Spontaneous emergence of Josephson junctions in homogeneous rings of single-crystal Sr2RuO4
Spontaneous emergence of Josephson junctions in homogeneous rings of single-crystal Sr2RuO4
复制标题
DOI：
10.1038/s41535-020-0223-7
复制
发表时间：
2019-03
影响因子：
5.7
通讯作者：
Y. Yasui;K. Lahabi;V. Becerra;R. Fermin;M. Anwar;S. Yonezawa;T. Terashima;M. Milovsevi'c;J. Aarts;Y. Maeno
中科院分区：
文献类型：
--
作者：
Y. Yasui;K. Lahabi;V. Becerra;R. Fermin;M. Anwar;S. Yonezawa;T. Terashima;M. Milovsevi'c;J. Aarts;Y. Maeno
sr2ruo4中的手性波序参数将使其成为非常规超导体中的一个特例。这种对称性的一个结果是可能存在手性相反的超导畴。在这些畴的边界处，局部抑制的凝聚可以产生本征约瑟夫森结。在这里，我们使用sr2ruo4单晶结构的介观环提供了这种连接的证据。我们的序参数模拟预测这样的环在其臂上有稳定的畴壁。在环上的输运实验证实了这一点，在1.5 K处有一个急剧的转变，显示出明显的临界电流振荡，与通量量子相对应。相比之下，在3k左右宽跃迁的环路没有这样的结，并显示出标准的利特尔-帕克斯振荡。我们的分析表明，这些结是固有的起源，并为超导畴的存在提供了令人信服的理由。
The chiralp-wave order parameter in Sr2RuO4would 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 Sr2RuO4single 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.