Topological Exciton Fermi Surfaces in Two-Component Fractional Quantized Hall Insulators

Maissam Barkeshli, Chetan Nayak, Zlatko Papić, Andrea Young, Michael Zaletel

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


A wide variety of two-dimensional electron systems allow for independent control of the total and relative charge density of two-component fractional quantum Hall (FQH) states. In particular, a recent experiment on bilayer graphene (BLG) observed a continuous transition between a compressible and incompressible phase at total filling νT=12 as charge is transferred between the layers, with the remarkable property that the incompressible phase has a finite interlayer polarizability. We argue that this occurs because the topological order of νT=12 systems supports a novel type of interlayer exciton that carries Fermi statistics. If the fermionic excitons are lower in energy than the conventional bosonic excitons (i.e., electron-hole pairs), they can form an emergent neutral Fermi surface, providing a possible explanation of an incompressible yet polarizable state at νT=12. We perform exact diagonalization studies that demonstrate that fermionic excitons are indeed lower in energy than bosonic excitons. This suggests that a "topological exciton metal" hidden inside a FQH insulator may have been realized experimentally in BLG. We discuss several detection schemes by which the topological exciton metal can be experimentally probed.

Original languageEnglish (US)
Article number026603
JournalPhysical review letters
Issue number2
StatePublished - Jul 9 2018

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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