论文标题
在正常胰腺中的子仪状态的起源
Origin of subgap states in normal-insulator-superconductor van der Waals heterostructures
论文作者
论文摘要
范德华材料中的超导性，例如NBSE $ _ {2} $和TAS $ _ {2} $，从根本上是新颖的，这是由于维度，晶体对称性和强旋转轨耦合的影响。在这项工作中，我们通过使用MOS $ _ {2} $或Hexagonal Boron Nitride（HBN）作为隧道障碍，在NBSE $ _ {2} $上进行隧道光谱。我们通过研究各种异质结构设计来观察子量表激发并探测其起源。我们表明，nbse $ _ {2} $的边缘主机许多缺陷状态，这些状态与超导体和形式的Andreev绑定状态相结合。此外，通过隔离nbse $ _ {2} $ edge，我们表明子量表状态在Mos $ _ {2} $隧道屏障中无处不在，但在HBN隧道屏障中不存在，这表明MOS $ _ {2} $的缺陷是其起源。它们的磁性揭示了单线或双重型接地状态，并基于几乎消失的G因子或避免了子隙激发的交叉，我们强调了强旋转轨道耦合的作用。
Superconductivity in van der Waals materials, such as NbSe$_{2}$ and TaS$_{2}$, is fundamentally novel due to the effects of dimensionality, crystal symmetries, and strong spin-orbit coupling. In this work we perform tunnel spectroscopy on NbSe$_{2}$ by utilizing MoS$_{2}$ or hexagonal Boron Nitride (hBN) as a tunnel barrier. We observe subgap excitations and probe their origin by studying various heterostructure designs. We show that the edge of NbSe$_{2}$ hosts many defect states, which strongly couple to the superconductor and form Andreev bound states. Furthermore, by isolating the NbSe$_{2}$ edge we show that the subgap states are ubiquitous in MoS$_{2}$ tunnel barriers, but absent in hBN tunnel barriers, suggesting defects in MoS$_{2}$ as their origin. Their magnetic nature reveals a singlet or a doublet type ground state and based on nearly vanishing g-factors or avoided-crossing of subgap excitations we highlight the role of strong spin-orbit coupling.
