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

الأصل · EN

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 4e²/h, yet Fabry-Perot oscillations are strongly suppressed. The quantization arises for small opening angles θπ/3 and large radii ratios R₂/R₁10. We find that the condition for emergence of the n-th conductance step can be written as √nθ/π≪1. A brief comparison with the conductance spectra of graphene nanoribbons with parallel edges is also provided.