Helical edge states and fractional quantum Hall effect in a graphene electron-hole bilayer.
- Author(s): Sanchez-Yamagishi, Javier D
- Luo, Jason Y
- Young, Andrea F
- Hunt, Benjamin M
- Watanabe, Kenji
- Taniguchi, Takashi
- Ashoori, Raymond C
- Jarillo-Herrero, Pablo
- et al.
Published Web Locationhttps://arxiv.org/abs/1602.06815
Helical 1D electronic systems are a promising route towards realizing circuits of topological quantum states that exhibit non-Abelian statistics. Here, we demonstrate a versatile platform to realize 1D systems made by combining quantum Hall (QH) edge states of opposite chiralities in a graphene electron-hole bilayer at moderate magnetic fields. Using this approach, we engineer helical 1D edge conductors where the counterpropagating modes are localized in separate electron and hole layers by a tunable electric field. These helical conductors exhibit strong non-local transport signals and suppressed backscattering due to the opposite spin polarizations of the counterpropagating modes. Unlike other approaches used for realizing helical states, the graphene electron-hole bilayer can be used to build new 1D systems incorporating fractional edge states. Indeed, we are able to tune the bilayer devices into a regime hosting fractional and integer edge states of opposite chiralities, paving the way towards 1D helical conductors with fractional quantum statistics.