The enigma of the quantum Hall effect in graphene |
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Authors: | S. Das Sarma Kun Yang |
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Affiliation: | aCondensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742, USA;bNational High Magnetic Field Laboratory and Department of Physics, Florida State University, Tallahassee, FL 32306, USA |
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Abstract: | We apply Laughlin’s gauge argument to analyze the ν=0 quantum Hall effect observed in graphene when the Fermi energy lies near the Dirac point, and conclude that this necessarily leads to divergent bulk longitudinal resistivity in the zero temperature thermodynamic limit. We further predict that in a Corbino geometry measurement, where edge transport and other mesoscopic effects are unimportant, one should find the longitudinal conductivity vanishing in all graphene samples which have an underlying ν=0 quantized Hall effect. We argue that this ν=0 graphene quantum Hall state is qualitatively similar to the high field insulating phase (also known as the Hall insulator) in the lowest Landau level of ordinary semiconductor two-dimensional electron systems. We establish the necessity of having a high magnetic field and high mobility samples for the observation of the divergent resistivity as arising from the existence of disorder-induced density inhomogeneity at the graphene Dirac point. |
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Keywords: | A. Graphene D. Quantum Hall effect |
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