论文标题
分数量子厅状态的Andreev反射
Andreev reflection in the fractional quantum Hall state
论文作者
论文摘要
我们构建具有狭窄的超导氮化物（NBN）电极的高质量石墨烯的范德华设备，其中超导性和鲁棒的FQH共存。我们发现跨过两个FQH边缘的超导体穿过Andreev反射（CAR）。我们在类似粒子的分数填充物中观察到的CAR概率明显高于整数和孔偶联分数填充物中的CAR概率，并且与其他填充物不同，并且很大程度上取决于温度和磁场。此外，我们在整数填充物中发现了与填充的CAR概率，我们将其归因于NBN中的自旋轨道耦合，从而允许在自旋极化边缘之间进行Andreev反射。这些结果为实现基于石墨烯和NBN的FQH渗透杂种设备的新型拓扑超导阶段提供了一种途径。
We construct high-quality graphene-based van der Waals devices with narrow superconducting niobium nitride (NbN) electrodes, in which superconductivity and robust fqH coexist. We find crossed Andreev reflection (CAR) across the superconductor separating two fqH edges. Our observed CAR probabilities in the particle-like fractional fillings are markedly higher than those in the integer and hole-conjugate fractional fillings and depend strongly on temperature and magnetic field unlike the other fillings. Further, we find a filling-independent CAR probability in integer fillings, which we attribute to spin-orbit coupling in NbN allowing for Andreev reflection between spin-polarized edges. These results provide a route to realize novel topological superconducting phases in fqH-superconductor hybrid devices based on graphene and NbN.
