Electronic structure of monolayer antimonene nanoribbons under out-of-plane and transverse bias

TL;DR

This paper investigates how out-of-plane and transverse electric biases influence the electronic band structure of monolayer antimonene nanoribbons, revealing controllable band gap modifications and spin-splitting effects due to symmetry breaking and spin-orbit coupling.

Contribution

It introduces a tight-binding model that accurately reproduces ab initio results and demonstrates how external biases can tune the electronic properties of antimonene nanoribbons.

Findings

Perpendicular electric field increases the band gap.

Transverse bias reduces the band gap in a position-dependent manner.

Biases break inversion symmetry, causing spin-splitting of valence bands.

Abstract

A systematic study of the electronic properties of single layer Sb (antimonene) nanoribbons is presented. By using a 6-orbital tight-binding Hamiltonian, we study the electronic band structure of finite ribbons with zigzag or armchair termination. We show that there is good agreement between ab initio calculations and the tight-binding model. We study how the size of the gap can be controlled by applying an external bias potential. An electric field applied perpendicular to the antimonene layer is found to increase the band gap, while a transverse bias potential leads to a position dependent reduction of the band gap. Both kinds of bias potential break inversion symmetry of the crystal. This, together with the strong intrinsic spin-orbit coupling of antimonene, leads to spin-splitting of the valence band states.