Quantum capacitance and density of states of graphene

We report on measurements of the quantum capacitance in graphene as a function of charge carrier density. A resonant LC-circuit giving high sensitivity to small capacitance changes is employed. The density of states, which is directly proportional to the quantum capacitance, is found to be significa...

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Veröffentlicht in:Applied physics letters 2010-04, Vol.96 (15), p.152104-152104-3
Hauptverfasser: Dröscher, S., Roulleau, P., Molitor, F., Studerus, P., Stampfer, C., Ensslin, K., Ihn, T.
Format: Artikel
Sprache:eng
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Zusammenfassung:We report on measurements of the quantum capacitance in graphene as a function of charge carrier density. A resonant LC-circuit giving high sensitivity to small capacitance changes is employed. The density of states, which is directly proportional to the quantum capacitance, is found to be significantly larger than zero at and around the charge neutrality point. This finding is interpreted to be a result of potential fluctuations with amplitudes of the order of 100 meV in good agreement with scanning single-electron transistor measurements on bulk graphene and transport studies on nanoribbons.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.3391670