论文标题
超导性的三倍增强和在2D极限附近的外延铝膜中田间诱导的奇数配对的作用
Threefold enhancement of superconductivity and the role of field-induced odd-frequency pairing in epitaxial aluminum films near the 2D limit
论文作者
论文摘要
BCS理论在描述元素散装超导体方面已广泛成功。然而，随着这种超导体的长度尺度接近原子极限，维数以及超导体的环境会导致截然不同且无法预测的超导行为。在这里，我们报告了基于高分辨率扫描隧道显微镜/光谱（STM/STS）测量值时，我们报告了SI（111）上超薄外部外观Al膜的超导临界温度和间隙大小的三倍增强。在磁场中，Al膜显示了面积内磁场的II型行为和Meservey-Tedrow-Fulde（MTF）效应。使用空间分辨的光谱法，我们表征了MTF制度中的涡旋结构，并发现与典型的Abrikosov涡流有强偏差。我们通过计算来证实这些发现，这些发现揭示了奇数配对和顺磁性meissner效应的作用。这些结果说明了BCS超导体对降低性降低的两个显着影响，并提出了一个新的平台，用于研究大型磁场中的BCS超导性。
BCS theory has been widely successful at describing elemental bulk superconductors. Yet, as the length scales of such superconductors approach the atomic limit, dimensionality as well as the environment of the superconductor can lead to drastically different and unpredictable superconducting behavior. Here, we report a threefold enhancement of the superconducting critical temperature and gap size in ultrathin epitaxial Al films on Si(111), when approaching the 2D limit, based on high-resolution scanning tunneling microscopy/spectroscopy (STM/STS) measurements. In magnetic field, the Al films show type II behavior and the Meservey-Tedrow-Fulde (MTF) effect for in-plane magnetic fields. Using spatially resolved spectroscopy, we characterize the vortex structure in the MTF regime and find strong deviations from the typical Abrikosov vortex. We corroborate these findings with calculations that unveil the role of odd-frequency pairing and a paramagnetic Meissner effect. These results illustrate two striking influences of reduced dimensionality on a BCS superconductor and present a new platform to study BCS superconductivity in large magnetic fields.
