UNIGE document Scientific Article
previous document  unige:34926  next document
add to browser collection

Observation of Even Denominator Fractional Quantum Hall Effect in Suspended Bilayer Graphene

Fal’ko, Vladimir I.
Abanin, Dmitry A.
Published in Nano Letters. 2014, p. 140310104111005
Abstract We investigate low-temperature magneto-transport in recently developed, high-quality multiterminal suspended bilayer graphene devices, enabling the independent measurement of the longitudinal and transverse resistance. We observe clear signatures of the fractional quantum Hall effect with different states that are either fully developed, and exhibit a clear plateau in the transverse resistance with a concomitant dip in longitudinal resistance or incipient, and exhibit only a longitudinal resistance minimum. All observed states scale as a function of filling factor ν, as expected. An unprecedented even-denominator fractional state is observed at ν = −1/2 on the hole side, exhibiting a clear plateau in Rxy quantized at the expected value of 2h/e2 with a precision of 0.5%. Many of our observations, together with a recent electronic compressibility measurement performed in graphene bilayers on hexagonal boron-nitride (hBN) substrates, are consistent with a recent theory that accounts for the effect of the degeneracy between the N = 0 and N = 1 Landau levels in the fractional quantum Hall effect and predicts the occurrence of a Moore-Read type ν = −1/2 state. Owing to the experimental flexibility of bilayer graphene, which has a gate-dependent band structure, can be easily accessed by scanning probes, and can be contacted with materials such as superconductors, our findings offer new possibilities to explore the microscopic nature of even-denominator fractional quantum Hall effect.
Keywords Even-denominator fractional quantum Hall effectMultiterminal suspended bilayer grapheneNon-Abelian Moore-Read state
Full text
Article (Published version) (1.9 MB) - document accessible for UNIGE members only Limited access to UNIGE
Other version: http://pubs.acs.org/doi/abs/10.1021/nl5003922
(ISO format)
KI, Dongkeun et al. Observation of Even Denominator Fractional Quantum Hall Effect in Suspended Bilayer Graphene. In: Nano Letters, 2014, p. 140310104111005. https://archive-ouverte.unige.ch/unige:34926

201 hits

0 download


Deposited on : 2014-03-24

Export document
Format :
Citation style :