Edge-passivation modulation of the transport properties in zigzag stanene nanoribbons

We study the combined effect of the passivating atoms, edge electric fields, and exchange fields on the edge states, conductance, and spin polarization in zigzag stanene nanoribbons (ZSNRs). The distortion direction and amplitude of edge bands significantly depend on the electronegativity difference between the passivating atoms and tin atoms. The conductance dips can reflect the curved characteristic of the edge bands induced by passivating atoms, which can be used to detect the quantum spin-Hall edge states or passivating atoms. Interestingly, the edge antisymmetric electric fields can recover the passivation-induced band structures and transport properties, and an effective spin polarization can be realized by applying an exchange field on the edges of ZSNRs. The results provide a comprehensive understanding of the modulating method by utilizing the passivating atoms and the external fields, which will be of great help for the application of stanene devices.