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. We find a possible signature for crossed Andreev reflection (CAR) across the superconducto...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2022-06-01
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| Series: | Physical Review X |
| Online Access: | http://doi.org/10.1103/PhysRevX.12.021057 |
| _version_ | 1828334612240138240 |
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| author | Önder Gül Yuval Ronen Si Young Lee Hassan Shapourian Jonathan Zauberman Young Hee Lee Kenji Watanabe Takashi Taniguchi Ashvin Vishwanath Amir Yacoby Philip Kim |
| author_facet | Önder Gül Yuval Ronen Si Young Lee Hassan Shapourian Jonathan Zauberman Young Hee Lee Kenji Watanabe Takashi Taniguchi Ashvin Vishwanath Amir Yacoby Philip Kim |
| author_sort | Önder Gül |
| collection | DOAJ |
| description | 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. We find a possible signature for crossed Andreev reflection (CAR) across the superconductor separating two FQH edges. Our observed CAR probabilities in the particlelike 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. |
| first_indexed | 2024-04-13T21:35:28Z |
| format | Article |
| id | doaj.art-8d04a168cd8b489fbcef83bd35496549 |
| institution | Directory Open Access Journal |
| issn | 2160-3308 |
| language | English |
| last_indexed | 2024-04-13T21:35:28Z |
| publishDate | 2022-06-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review X |
| spelling | doaj.art-8d04a168cd8b489fbcef83bd354965492022-12-22T02:29:01ZengAmerican Physical SocietyPhysical Review X2160-33082022-06-0112202105710.1103/PhysRevX.12.021057Andreev Reflection in the Fractional Quantum Hall StateÖnder GülYuval RonenSi Young LeeHassan ShapourianJonathan ZaubermanYoung Hee LeeKenji WatanabeTakashi TaniguchiAshvin VishwanathAmir YacobyPhilip KimWe 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. We find a possible signature for crossed Andreev reflection (CAR) across the superconductor separating two FQH edges. Our observed CAR probabilities in the particlelike 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.http://doi.org/10.1103/PhysRevX.12.021057 |
| spellingShingle | Önder Gül Yuval Ronen Si Young Lee Hassan Shapourian Jonathan Zauberman Young Hee Lee Kenji Watanabe Takashi Taniguchi Ashvin Vishwanath Amir Yacoby Philip Kim Andreev Reflection in the Fractional Quantum Hall State Physical Review X |
| title | Andreev Reflection in the Fractional Quantum Hall State |
| title_full | Andreev Reflection in the Fractional Quantum Hall State |
| title_fullStr | Andreev Reflection in the Fractional Quantum Hall State |
| title_full_unstemmed | Andreev Reflection in the Fractional Quantum Hall State |
| title_short | Andreev Reflection in the Fractional Quantum Hall State |
| title_sort | andreev reflection in the fractional quantum hall state |
| url | http://doi.org/10.1103/PhysRevX.12.021057 |
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