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arXiv · 1805.05680

Coherent Transport in Y-Junction Graphene Waveguide

Vahid Mosallanejad·Kuei-Lin Chiu·Guo-ping Guo
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Abstract

We performed a series of theoretical transport studies on Y-branch electron waveguides which are embedded in mid-size armchair graphene nanoribbons (AGNRs). Non-equilibrium Greens function (NEGF) with different approximations of tight-binding (TB) Hamiltonian has been employed. Using the first nearest hopping approximation, we observed very pronounced conductance quantization, the structure of which depends on geometrical design and shows a spacing of $4e^2/h$, indicating the existence of valley degree of freedom. Moreover, by incorporating the third nearest approximation, we observed seminal plateaus deviated from multiples of $4e^2/h$ conductance, suggesting the lift of valley degeneracy. Finally, Quasi-one dimensional band structure calculations have been performed to study the availability of energy channels and the role of the major geometrical parameters on the transport.

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Vahid Mosallanejad, Kuei-Lin Chiu, Guo-ping Guo. 2018-05-15. Coherent Transport in Y-Junction Graphene Waveguide. https://doi.org/10.1088/1361-648x%2Faae09d

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