| Summary: | 碩士 === 國立成功大學 === 物理學系碩博士班 === 98 === Few-layer graphenes have attracted a lot of attentions since they are achieved by recent experiments. Graphene is kind of ideal two-dimensional materials, and its honeycomb lattice results in the extraordinary electronic properties. The energy bands would be effectively influenced the interlayer interactions, and significantly modulated by external magnetic or electric fields. In this work, we employ the Peierls tight-binding model to evaluate the magneto-electronic structures of bilayer Bernal graphene. The magnetic and electric field, together with the interlayer interactions, are taken into account simultaneously. The field dependence of Landau energies and wave functions are investigated in detail.
The bilayer Bernal graphene possesses two pairs of parabolic bands in the low energy regions. And the perpendicular magnetic field substantially quantizes these energy bands into two groups of Landau levels. The degeneracy of these Landau states would be lifted by the external electric field, where the energy spacings split are broadened with field strength. The variation degree of the two lowest Landau levels is particularly evident. In addition, the wave function of Landau levels is governed by four sublattices. The way the wave function distributed over its subblattices would further vary with electric or magnetic fields.
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