Spin-orbit coupling effects on the electronic properties of stanene and fluorinated stanene armchair nanoribbons

We have studied the electronic properties of armchair stanene and fluorinated stanene nanoribbons by using first principle calculations including the spin-orbit coupling (SOC). In the case of stanene we found that the band gaps oscillate with the width of the nanoribbon due to the quantization condition. While, for fluorinated stanene nanoribbons the band gap decreases monotonically with increasing width and tend to zero if we included the SOC. We also studied the real space charge distribution. For analyzed sizes of stanene nanoribbons we did not find a localization of the charge distribution at the edges when we include the SOC. On the contrary, there is a charge localization at the edges in fluorinated stanene nanoribbons when we include the SOC. The above results shows that fluorinated stanene shows a behavior typical of a Topological Insulator.