Abstract
The discovery of the quantum spin Hall effect led to the exploration of the electronic transport for spintronic devices. Here, we theoretically investigated the electronic conductance in large-gap realistic quantum spin Hall system, Pt₂HgSe₃ nanoribbons. By an ab initio approach, we found that the edge states present a penetration depth of about 0.9\,{nm}, which is much smaller than those predicted in other 2D topological systems. Thus, suggesting that Pt₂HgSe₃ allows the exploitation of topological transport properties in narrow ribbons. Using non-equilibrium Green's functions calculations, we have examined the electron conductivity upon the presence of Se\,↔\,Hg antistructure defects randomly distributed in the Pt₂HgSe₃ scattering region. By considering scattering lengths up to 109\,nm, we found localization lengths that can surpass μm sizes for narrow nanoribbons (<9\,nm). These findings can contribute to further understanding the behavior of topological insulators under realistic conditions and their integration within electronic, spintronic devices.