Abstract
In this work, we study the transport through a quantum point contact for bosonic helical liquid that exists at the edge of a bilayer graphene under a strong magnetic field. We identify “smoking gun” transport signatures to distinguish a bosonic symmetry-protected topological (BSPT) state from a fermionic two-channel quantum spin Hall (QSH) state in this system. In particular, a novel charge-insulator–spin-conductor phase is found for the BSPT state, while either the charge-insulator–spin-insulator or the charge-conductor–spin-conductor phase is expected for the two-channel QSH state. Consequently, a simple transport measurement will reveal the fingerprint of bosonic topological physics in bilayer graphene systems.
- Received 24 October 2016
DOI:https://doi.org/10.1103/PhysRevLett.118.216803
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