论文标题
非接触式Andreev反射作为原子量表上超导性的直接探针
Non-contact Andreev reflection as a direct probe of superconductivity on the atomic scale
论文作者
论文摘要
长期以来，直接检测超导性一直是点接触反射的关键强度。但是，其对原子尺度成像的适用性受Andreev探针的机械接触限制。为此，我们提出了一种在隧道连接处探测安德里弗反射的新方法，利用隧道光谱和连接可调性来实现Andreev散射的定量检测。该方法使得携带激发的超导起源以及检测原子级连接中的高级安德里夫过程的明确分配。此外，我们揭示了安德里·反射对自然缺陷的明显敏感性，例如阶梯边缘，即使在经典的超导体中也是如此。该方法为超导特性的纳米和原子尺度成像开辟了一条新的途径，包括无序的超导体和与相变的接近度。
Direct detection of superconductivity has long been a key strength of point-contact Andreev reflection. However, its applicability to atomic-scale imaging is limited by the mechanical contact of the Andreev probe. To this end, we present a new method to probe Andreev reflection in a tunnel junction, leveraging tunneling spectroscopy and junction tunability to achieve quantitative detection of Andreev scattering. This method enables unambiguous assignment of superconducting origins of current-carrying excitations as well as detection of higher order Andreev processes in atomic-scale junctions. We furthermore revealed distinct sensitivity of Andreev reflection to natural defects, such as step edges, even in classical superconductors. The methodology opens a new path to nanoand atomic-scale imaging of superconducting properties, including disordered superconductors and proximity to phase transitions.
