2007/06/30 by A. J. M. Giesbers, U. Zeitler, M. I. Katsnelson +6
Engineering · Materials Science · Physics and Astronomy · #Graphene research and applications #Magnetic Field Sensors Techniques #Quantum and electron transport phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.99.206803
published as Phys. Rev. Lett. 99, 206803 (2007) · 4 pages, 4 figures, updated version after review, accepted for PRL
arxiv created 2007/10/12 · openalex publication_date 2007/11/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have measured the quantum-Hall activation gaps in graphene at filling factors \ensuremathν=2 and \ensuremathν=6 for magnetic fields up to 32 T and temperatures from 4 to 300 K. The \ensuremathν=6 gap can be described by thermal excitation to broadened Landau levels with a width of 400 K. In contrast, the gap measured at \ensuremathν=2 is strongly temperature and field dependent and approaches the expected value for sharp Landau levels for fields B>20 T and temperatures T>100 K. We explain this surprising behavior by a narrowing of the lowest Landau level.