Atomistic Non-equilibrium Green s Function Simulations of Graphene Nano-Ribbons in the Quantum Hall Regime

摘要

The quantum Hall effect in Graphene nano-ribbons (GNR) is investigated withthe non-equilibrium Green s function (NEGF) based quantum transport model inthe ballistic regime. The nearest neighbor tight-binding model based on pzorbital constructs the device Hamiltonian. GNRs of different edge geometries(Zigzag and Armchair) are considered. The magnetic field is included in boththe channels and contact through Peierls substitution. Efficient algorithms forcalculating the surface Green function are used to save computation time whilesimulating realistically large dimensions comparable to those used inexperiments. Hall resistance calculations exactly reproduce the quantum Hallplateaus observed in the experiments. Use of large dimensions in the simulationis crucial in order to capture the quantum Hall effect in magnetic fieldswithin experimentally relevant 10-20T.