AI 中文总结
研究扭曲NbSe2/NbSe2范德华结中超导输运，通过干法转移制备结并利用高分辨率透射电镜确定扭曲角等。发现约瑟夫森耦合强度与扭曲角有关，而超电流二极管效率与扭曲角无关，界面无序才是二极管响应主因，解耦了两者关系并提供基准。
AI 中文摘要
范德华约瑟夫森结中超电流非互易性的微观起源仍在积极争论中，特别是关于层状超导体中扭曲角工程的作用。在此，我们研究了通过干法转移制备的具有可控晶体取向和化学清洁界面的扭曲NbSe2/NbSe2垂直约瑟夫森结中的超导输运。采用高分辨率透射电子显微镜直接确定扭曲角并评估界面质量。虽然约瑟夫森耦合强度对扭曲角有明显依赖性，在晶体学等效取向附近特征电压最大，在中间角度受到抑制，但超电流二极管效率仍然可以忽略不计且没有系统的扭曲角依赖性。相反，增强的二极管样响应仅出现在表现出界面无序和透明度降低的弱耦合结中。故意的界面退化进一步放大了表观非互易性，产生接近30%的二极管效率以及不规则的磁场强度依赖性。这些结果在扭曲的NbSe2/NbSe2结中建立了约瑟夫森耦合与超电流非互易性之间的明确解耦。我们的发现确定界面无序而非扭曲角控制的动量匹配是观察到的二极管响应的主要起源，并为解释范德华约瑟夫森器件中的非互易超导输运提供了关键基准。
英文摘要
The microscopic origin of supercurrent nonreciprocity in van der Waals Josephson junctions remains under active debate, particularly regarding the role of twist-angle engineering in layered superconductors. Here, we investigate superconducting transport in twisted NbSe2/NbSe2 vertical Josephson junctions fabricated by dry transfer with controlled crystallographic alignment and chemically clean interfaces. High-resolution transmission electron microscopy is employed to directly determine the twist angle and assess interface quality. While the Josephson coupling strength exhibits a pronounced dependence on twist angle, with characteristic voltages maximized near crystallographically equivalent orientations and suppressed at intermediate angles, the supercurrent diode efficiency remains negligibly small and shows no systematic twist-angle dependence. In contrast, enhanced diode-like responses emerge only in weakly coupled junctions exhibiting interfacial disorder and reduced transparency. Deliberate interface degradation further amplifies the apparent nonreciprocity, yielding diode efficiencies approaching 30% together with an irregular magnetic-field-strength dependence. These results establish a clear decoupling between Josephson coupling and supercurrent nonreciprocity in twisted NbSe2/NbSe2 junctions. Our findings identify interface disorder, rather than twist-angle-controlled momentum matching, as the dominant origin of the observed diode response and provide a critical benchmark for interpreting nonreciprocal superconducting transport in van der Waals Josephson devices.
Comments28 pages, 6 figures
