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Motivated by the observation of even denominator fractional quantum Hall effect in the n= 3 Landau level of monolayer graphene [Kim et al., Nat. Phys. 15, 154 (2019)], we consider a Bardeen-Cooper-Schrieffer variational state for composite fermions and find that the composite-fermion Fermi sea in this Landau level is unstable to an f-wave pairing. Analogous calculation suggests the possibility of a p-wave pairing of composite fermions at half filling in the n= 2 graphene Landau level, whereas no pairing instability is found at half filling in the n= 0 and n= 1 graphene Landau levels. The relevance of these results to experiments is discussed.
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This content will become publicly available on March 17, 2026
Detection of fractional quantum Hall states by entropy-sensitive measurements
The thermopower of a clean two-dimensional electron system is directly proportional to the entropy per charge carrier and can probe strongly interacting quantum phases such as fractional quantum Hall liquids. In particular, thermopower is a valuable parameter to probe the quasiparticle statistics that give rise to excess entropy in certain even-denominator fractional quantum Hall states. Here we demonstrate that the magneto-thermopower detection of fractional quantum Hall states is more sensitive than resistivity measurements. We do this in the context of Bernal-stacked bilayer graphene and highlight several even-denominator states at a relatively low magnetic feld. These capabilities of thermopower measurements support the interest in fractional quantum Hall states for fnding quasiparticles with non-Abelian statistics and elevate bilayer graphene as a promising platform for achieving this.
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- PAR ID:
- 10581909
- Publisher / Repository:
- Springer Nature, Nature Physics
- Date Published:
- Journal Name:
- Nature Physics
- ISSN:
- 1745-2473
- Subject(s) / Keyword(s):
- Fractional quantum Hall effect, thermopower, 2D materials, bilayer graphene
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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