Composite fermions and broken symmetries in graphene

F. Amet (), A. J. Bestwick, J. R. Williams, L. Balicas, K. Watanabe, T. Taniguchi and D. Goldhaber-Gordon ()
Additional contact information
F. Amet: Stanford University
A. J. Bestwick: Stanford University
J. R. Williams: Stanford University
L. Balicas: National High Magnetic Field Laboratory
K. Watanabe: Advanced Materials Laboratory, National Institute for Materials Science
T. Taniguchi: Advanced Materials Laboratory, National Institute for Materials Science
D. Goldhaber-Gordon: Stanford University

Nature Communications, 2015, vol. 6, issue 1, 1-7

Abstract: Abstract The electronic properties of graphene are described by a Dirac Hamiltonian with a four-fold symmetry of spin and valley. This symmetry may yield novel fractional quantum Hall (FQH) states at high magnetic field depending on the relative strength of symmetry-breaking interactions. However, observing such states in transport remains challenging in graphene, as they are easily destroyed by disorder. In this work, we observe in the first two Landau levels the two-flux composite-fermion sequences of FQH states between each integer filling factor. In particular, the odd-numerator fractions appear between filling factors 1 and 2, suggesting a broken-valley symmetry, consistent with our observation of a gap at charge neutrality and zero field. Contrary to our expectations, the evolution of gaps in a parallel magnetic field suggests that states in the first Landau level are not spin-polarized even up to very large out-of-plane fields.

Date: 2015
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/ncomms6838 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:6:y:2015:i:1:d:10.1038_ncomms6838

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/ncomms6838

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().