Supercurrent mediated by helical edge modes in bilayer graphene
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2023
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866914724137926656 |
|---|---|
| author | Rout, Prasanna Papadopoulos, Nikos Peñaranda, Fernando Watanabe, Kenji Taniguchi, Takashi Prada, Elsa San-Jose, Pablo Goswami, Srijit |
| author_facet | Rout, Prasanna Papadopoulos, Nikos Peñaranda, Fernando Watanabe, Kenji Taniguchi, Takashi Prada, Elsa San-Jose, Pablo Goswami, Srijit |
| contents | 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. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2305_10505 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Supercurrent mediated by helical edge modes in bilayer graphene Rout, Prasanna Papadopoulos, Nikos Peñaranda, Fernando Watanabe, Kenji Taniguchi, Takashi Prada, Elsa San-Jose, Pablo Goswami, Srijit Mesoscale and Nanoscale Physics 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. |
| title | Supercurrent mediated by helical edge modes in bilayer graphene |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2305.10505 |