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arXiv · 1107.4326

Coulomb Gap in Graphene Nanoribbons

S. Dröscher·H. Knowles·Y. Meir·K. Ensslin·T. Ihn
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Abstract

We investigate the density and temperature-dependent conductance of graphene nanoribbons with varying aspect ratio. Transport is dominated by a chain of quantum dots forming spontaneously due to disorder. Depending on ribbon length, electron density, and temperature, single or multiple quan- tum dots dominate the conductance. Between conductance resonances cotunneling transport at the lowest temperatures turns into activated transport at higher temperatures. The density-dependent activation energy resembles the Coulomb gap in a quantitative manner. Individual resonances show signatures of multi-level transport in some regimes, and stochastic Coulomb blockade in others.

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S. Dröscher, H. Knowles, Y. Meir, K. Ensslin, T. Ihn. 2011-10-08. Coulomb Gap in Graphene Nanoribbons. https://doi.org/10.1103/physrevb.84.073405

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