DFT study with van der Waals interactions of surface state electronic properties of As-doped \(Bi_2 Se_3\) topological insulator

Topological Insulators (TIs), are the trending materials for future prospects of spintronics and quantum computing that make better computers. However, the large spin-orbit interaction results in some fascinating electronic properties. The TIs are the insulators with open band gap in bulk and is protected by their time-reversal symmetry while their surface state is metallic. In this work, we investigate surface state electronic properties of Arsenic (As) doped \(Bi_2Se_3\) $B{i}_{2}S{e}_3$ with the help of DFT with van der Waals interaction. The surface state contains 5 quintuple layers (ql) where each layer is stacked as Se-Bi-Se-Bi-Se and separated by van der Waals gap. Doping of As atom in \(Bi_2Se_3\) $B{i}_{2}S{e}_3$ changes the surface electronic structure which leads to potential technical applications. The detailed study includes the comparison of band structure and density of states (DOS) without and with spin-orbit coupling (SOC) of As doped \(Bi_2Se_3\) $B{i}_{2}S{e}_3$ topological quantum materials.