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arXiv · 1105.0274

Time-resolved charge detection in graphene quantum dots

J. Guettinger·J. Seif·C. Stampfer·A. Capelli·K. Ensslin·T. Ihn
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Abstract

We present real-time detection measurements of electron tunneling in a graphene quantum dot. By counting single electron charging events on the dot, the tunneling process in a graphene constriction and the role of localized states are studied in detail. In the regime of low charge detector bias we see only a single time-dependent process in the tunneling rate which can be modeled using a Fermi-broadened energy distribution of the carriers in the lead. We find a non-monotonic gate dependence of the tunneling coupling attributed to the formation of localized states in the constriction. Increasing the detector bias above 2 mV results in an increase of the dot-lead transition rate related to back-action of the charge detector current on the dot.

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J. Guettinger, J. Seif, C. Stampfer, A. Capelli, K. Ensslin, T. Ihn. 2011-05-02. Time-resolved charge detection in graphene quantum dots. https://doi.org/10.1103/physrevb.83.165445

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