Supercurrent mediated by helical edge modes in bilayer graphene

التفاصيل البيبلوغرافية
العنوان: Supercurrent mediated by helical edge modes in bilayer graphene
المؤلفون: Rout, Prasanna, Papadopoulos, Nikos, Peñaranda, Fernando, Watanabe, Kenji, Taniguchi, Takashi, Prada, Elsa, San-Jose, Pablo, Goswami, Srijit
المصدر: Nat Commun 15, 856 (2024)
سنة النشر: 2023
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: Bilayer graphene encapsulated in tungsten diselenide can host a weak topological phase with pairs of helical edge states. The electrical tunability of this phase makes it an ideal platform to investigate unique topological effects at zero magnetic field, such as topological superconductivity. Here we couple the helical edges of such a heterostructure to a superconductor. The inversion of the bulk gap accompanied by helical states near zero displacement field leads to the suppression of the critical current in a Josephson geometry. Using superconducting quantum interferometry we observe an even-odd effect in the Fraunhofer interference pattern within the inverted gap phase. We show theoretically that this effect is a direct consequence of the emergence of helical modes that connect the two edges of the sample. The absence of such an effect at high displacement field, as well as in bare bilayer graphene junctions, confirms this interpretation and demonstrates the topological nature of the inverted gap. Our results demonstrate the coupling of superconductivity to zero-field topological states in graphene.
Comment: 13 pages, 14 figures
نوع الوثيقة: Working Paper
DOI: 10.1038/s41467-024-44952-6
URL الوصول: http://arxiv.org/abs/2305.10505
رقم الأكسشن: edsarx.2305.10505
قاعدة البيانات: arXiv
الوصف
DOI:10.1038/s41467-024-44952-6