标题： 薄膜不对称弱连接中超电流的受控整流 显示英文标题

标题： Streamline controlled rectification of supercurrent in thin-film asymmetric weak links

摘要： 在本研究中，我们检查了由不对称Dayem桥形成的介观超导弱连接中的超电流二极管效应（SDE）。这些平面金属收缩区自然表现出约瑟夫森类似行为，为在桥宽度与超导相干长度相匹配的区域研究非互易输运现象提供了一个基本平台。该基本概念受到特斯拉阀的启发，这是一种经典的流体装置，通过几何不对称性实现流体流的整流。类似地，我们证明了超导结构内的空间不对称性可以导致整流，这是由于输运电流和屏蔽电流之间的极性依赖相互作用所致。通过在收缩区与超导电极之间的结处引入受控的几何缺陷，我们诱导电流聚集并破坏空间反演对称性，从而实现方向切换行为。实验结果表明，在低磁场下存在线性磁场整流区域，这是由输运电流和屏蔽电流之间的相互作用驱动的，并且在高磁场下被超导库中的复杂涡旋动力学所取代。时间依赖的Ginzburg-Landau模拟再现了实验观察的重要特征，并证实了屏蔽电流和阿布里科索夫涡旋重新排列的影响。对各种几何结构的比较研究突显了缺陷形状和空间限制在决定整流效率中的关键作用，揭示了桥宽度存在一个最小阈值，低于该阈值时，由于电流聚集引起的SDE显著降低。我们的发现提倡使用介观Dayem桥作为设计和控制超导二极管功能的灵活平台。 显示英文摘要

摘要： In this study, we examined the supercurrent diode effect (SDE) in mesoscopic superconducting weak links formed by asymmetric Dayem bridges. These planar metallic constrictions, which naturally exhibit Josephsonlike behavior, offer a fundamental platform for investigating nonreciprocal transport phenomena in a regime where the bridge width aligns with the superconducting coherence length. The foundational concept is inspired by the Tesla valve, a classical fluidic device that achieves flow rectification through interference and turbulence between fluid streams enabled by geometric asymmetry. Analogously, we demonstrate that spatial asymmetry within superconducting structures can result in rectification due to the polarity-dependent interaction between transport and screening currents. By implementing controlled geometric defects at the junction between the constriction and superconducting leads, we induce current crowding and disrupt spatial inversion symmetry, thus facilitating directional switching behavior. Experimental results indicate a linear-in-field rectification regime at low magnetic fields, driven by the interaction between transport and screening currents, which is succeeded by complex vortex dynamics within the superconducting banks at elevated fields. Time-dependent Ginzburg-Landau simulations replicate significant features of the experimental observations and substantiate the influence of both screening currents and rearrangements of Abrikosov vortices. A comparative study across various geometries highlights the crucial role of defect shape and spatial confinement in determining the rectification efficiency, revealing a minimum threshold in bridge width below which crowding-induced SDE is significantly reduced. Our findings advocate for mesoscopic Dayem bridges as a flexible platform for designing and controlling superconducting diode functionalities.