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تسجيل مستخدم جديدTheory of the Room-Temperature QHE in Graphene
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The unusual quantum Hall effect (QHE) in graphene is often discussed in terms of Dirac fermions moving with a linear dispersion relation. The same phenomenon will be explained in terms of the more traditional composite bosons, which move with a linear dispersion relation. The electron (wave packet) moves easier in the direction [1,1,0,c-axis] = [1,1,0] of the honeycomb lattice than perpendicular to it, while the hole moves easier in [0,0,1]. Since electrons and holes move in different channels, the number densities can be high especially when the Fermi surface has necks. The strong QHE arises from the phonon exchange attraction in the neighborhood of the neck Fermi surfaces. The plateau observed for the Hall conductivity and the accompanied resistivity drop is due to the Bose-Einstein condensation of the c-bosons, each forming from a pair of one-electron--two-fluxons c-fermions by phonon-exchange attraction.
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