Electronic properties of germanene nanoribbons in external fields

Germanene nanoribbons, with buckled structures, exhibit unique electronic properties. The complicated relations among the quantum confinement, the spin-orbital coupling, the magnetic quantization, the electric-field dominated quantum numbers, energy dispersions, energy gap, state degeneracy, and wave functions. Such mechanisms can diversify spatial charge distributions and spin configurations on distinct sublattices. There exist the spin-split quasi-Landau levels and the valley-dependent asymmetric energy spectrum in a composite electric and magnetic field, manly owing to the destruction of z=0 mirror symmetry. The rich electronic structures are revealed in density of states as a lot of special structures. The predicted results could be directly verified by the scanning tunneling spectroscopy.