Andreev Reflection in the Fractional Quantum Hall State

We construct high-quality graphene-based van der Waals devices with narrow superconducting niobium nitride (NbN) electrodes, in which superconductivity and a robust fractional quantum Hall (FQH) state coexist. find possible signature for crossed Andreev reflection (CAR) across the superconductor separating two FQH edges. Our observed CAR probabilities particlelike fillings are markedly higher than those integer hole-conjugate depend strongly on temperature magnetic field unlike other fillings. Further, we filling-independent probability fillings, attribute to spin-orbit coupling NbN allowing between spin-polarized These results provide route realize novel topological phases FQH-superconductor hybrid based graphene NbN.13 MoreReceived 20 September 2021Accepted 4 May 2022DOI:https://doi.org/10.1103/PhysRevX.12.021057Published by American Physical Society under terms of Creative Commons Attribution 4.0 International license. Further distribution this work must maintain attribution author(s) published article’s title, journal citation, DOI.Published SocietyPhysics Subject Headings (PhySH)Research AreasFractional effectTopological superconductorsCondensed Matter, Materials & Applied Physics