发表机构
National Institute of Standards and Technology; University of Colorado Boulder; SUN Magnetics (RF) (Pty) Ltd; Stellenbosch University（美国国家标准与技术研究院; 科罗拉多大学博尔德分校; SUN Magnetics (RF) 私人有限公司; 斯泰伦博斯大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用扫描超导量子干涉显微镜直接关联直流超导量子干涉器件性能与捕获磁通位置，发现无论护城河配置如何均存在优先钉扎位点，为电路布局与故障分析提供反馈。
AI 中文摘要
超导电路地平面中的孔洞（通常称为“护城河”）已知是缓解超导电路中残余磁通有害影响的有效手段。先前的研究利用扫描超导量子干涉显微镜（SSM）对多种护城河几何结构的有效性以及它们不再阻止地平面中涡旋的最大磁场进行了成像，但未直接将磁通位置与电路性能测量相关联。在本研究中，我们采用SSM对多种护城河配置在直流超导量子干涉器件（DC SQUID）附近捕获不需要磁通的有效性进行成像，并在护城河失效时，对地平面中涡旋的位置进行成像。在同一次冷却过程中，且不干扰电路的情况下，我们测量电路性能以直接将其与涡旋位置相关联。我们表明，无论护城河配置如何，都存在磁通子的优先钉扎位点，这证明了SSM在电路布局、建模和故障分析中提供反馈的实用性。
英文摘要
Holes in the ground planes of superconducting circuits, commonly referred to as moats, are known to be an effective means of mitigating the deleterious effects of residual magnetic flux in superconducting circuits. Previous studies have utilized scanning SQUID microscopy (SSM) to image the effectiveness of various moat geometries and the maximum magnetic fields where they no longer prevent vortices in the ground plane but have not directly correlated the location of flux with circuit performance measurements. In this study we employ SSM to image the effectiveness of various moat configurations in trapping unwanted flux near a DC SQUID, and when the moats are not effective, the location of vortices in the ground plane. During the same cooldown, and without disturbing the circuit, we measure the circuit performance to directly correlate this with the vortex location. We show that there are preferential pinning sites for fluxons regardless of moat configuration, demonstrating the utility of the SSM in provide feedback for circuit layout, modeling, and failure analysis.
