Protected edge states in silicene antidots and dots in magnetic field

TL;DR

This paper investigates topological edge states in silicene antidots and dots under magnetic fields, highlighting their robustness against edge roughness and their valley-spin polarization due to intrinsic spin-orbit interactions.

Contribution

It demonstrates the existence and robustness of protected edge states in silicene nanostructures with various edge terminations, including rough edges, in a magnetic field.

Findings

Protected edge states propagate along the perimeter in both ideal and rough edges.

Edge roughness reduces valley polarization and energy slope.

Topological states are robust against atomic-scale edge imperfections.

Abstract

Silicene systems, due to the buckled structure of the lattice, manifest remarkable intrinsic spin-orbit interaction triggering a topological phase transition in the low-energy regime. Thus, we found that protected edge states are present in silicene antidots and dots, being polarized in valley-spin pairs. We have also studied the effect of the lattice termination on the properties of the single electron energy levels and electron density distribution of silicene antidots and dots situated in a perpendicular magnetic field. Our calculations confirmed that the topological edge states are propagating over the perimeter of the antidot/dot for both ideal or realistic edge termination containing roughness on the atomic length scale. The valley polarization and the slope of the energy line as a function of the magnetic field is, however, reduced when the antidot or dot has a rough edge.