Intra-Landau-level magnetoexcitons and the transition between quantum Hall states in undoped bilayer graphene

Toke, Csaba and Falko, Vladimir (2011) Intra-Landau-level magnetoexcitons and the transition between quantum Hall states in undoped bilayer graphene. Physical review B, 83 (11). ISSN 1098-0121

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Abstract

We study the collective modes of the quantum Hall states in undoped bilayer graphene in a strong perpendicular magnetic and electric field. Both for the well-known ferromagnetic state that is relevant for small electric field E-perpendicular to and the analogous layer polarized one suitable for large E-perpendicular to, the low-energy physics is dominated by magnetoexcitons with zero angular momentum that are even combinations of excitons that conserve Landau orbitals. We identify a long-wavelength instability in both states, and argue that there is an intermediate range of the electric field E-c((1)) < E-perpendicular to < E-c((s)) where a gapless phase interpolates between the incompressible quantum Hall states. The experimental relevance of this crossover via a gapless state is discussed.

Item Type:
Journal Article
Journal or Publication Title:
Physical review B
Additional Information:
©2011 American Physical Society
Uncontrolled Keywords:
/dk/atira/pure/researchoutput/libraryofcongress/qc
Subjects:
ID Code:
56990
Deposited By:
Deposited On:
15 Aug 2012 11:23
Refereed?:
Yes
Published?:
Published
Last Modified:
11 Jul 2020 04:14