Effects of Transverse Electric Fields on Quasi-Landau Levels in Zigzag Graphene Nanoribbons

The magnetoelectronic properties of one-dimensional zigzag graphene nanoribbons are investigated using the Peierls tight-binding model with uniform magnetic and electric fields. They are mainly determined by external fields and quantum confinement effects. Magnetic fields lead to quasi-Landau levels (QLLs), enhance partial flat bands, and result in Landau wave functions. Electric fields significantly distort dispersionless QLLs, change the band symmetry, induce more band-edge states, split partial flat bands, and drastically alter the distribution of wave functions. The density of states directly reflects the main features of energy bands, such as the numbers, frequencies, heights, and divergence forms of prominent peaks, which can be confirmed experimentally. Magneto-optical absorption spectra are predicted to be markedly changed under the influence of external electric fields.