Conditions for Conductance Quantization in Mesoscopic Dirac Systems on the Examples of Graphene Nanoconstrictions

Abstract

Ballistic transport through an impurity-free section of the Corbino disk in graphene is investigated by means of the Landauer-Büttiker formalism in the mesoscopic limit. In the linear-responce regime the conductance is quantized in steps close to integer multiples of $4e^2/h$, yet Fabry-Perot oscillations are strongly suppressed. The quantization arises for small opening angles $\theta \lesssim \pi /3$ and large radii ratios $R_2/R_1\gtrsim 10$. We find that the condition for emergence of the $n$-th conductance step can be written as $\sqrt{n}\theta /\pi \ll 1$. A brief comparison with the conductance spectra of graphene nanoribbons with parallel edges is also provided.

Typos corrected. RevTeX, 5 pages, 4 figures. Presented on "XVI National Conference of Superconductivity", October 7-12, 2013, Zakopane, Poland

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Cited by in corpus (2)

• Lifshitz transition and thermoelectric properties of bilayer graphene
• Theory of the sub-Sharvin charge transport in graphene disks