Compact SQUID Realized in a Double-Layer Graphene Heterostructure
| Autor: | Takashi Taniguchi, Paritosh Karnatak, Péter Makk, Artem Kononov, Kenji Watanabe, Raphaelle Delagrange, Lujun Wang, David I. Indolese, Christian Schönenberger, Roy Haller |
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| Rok vydání: | 2020 |
| Předmět: |
Josephson effect
Materials science FOS: Physical sciences Bioengineering 02 engineering and technology law.invention law Condensed Matter::Superconductivity biology.animal Mesoscale and Nanoscale Physics (cond-mat.mes-hall) General Materials Science Superconductivity Double layer (biology) Squid Condensed Matter - Mesoscale and Nanoscale Physics biology business.industry Graphene Mechanical Engineering Heterojunction General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Optoelectronics Topological quantum computation 0210 nano-technology business |
| Zdroj: | Nano Letters |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | Two-dimensional systems that host one-dimensional helical states are exciting from the perspective of scalable topological quantum computation when coupled with a superconductor. Graphene is particularly promising for its high electronic quality, versatility in van der Waals heterostructures and its electron and hole-like degenerate 0$th$ Landau level. Here, we study a compact double layer graphene SQUID (superconducting quantum interference device), where the superconducting loop is reduced to the superconducting contacts, connecting two parallel graphene Josephson junctions. Despite the small size of the SQUID, it is fully tunable by independent gate control of the Fermi energies in both layers. Furthermore, both Josephson junctions show a skewed current phase relationship, indicating the presence of superconducting modes with high transparency. In the quantum Hall regime we measure a well defined conductance plateau of 2$e^2/h$ an indicative of counter propagating edge channels in the two layers. Our work opens a way for engineering topological superconductivity by coupling helical edge states, from graphene's electron-hole degenerate 0$th$ Landau level via superconducting contacts. 38 pages, 12 figures |
| Databáze: | OpenAIRE |
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