First-principles modeling of electrostatics and transport in 2D topological transistors

We develop a simulation framework for electrostatic and transport modeling of 2D topological insulator field-effect transistors (2D TIFETs), based solely on first-principles calculations using density functional theory (DFT). We find that careful consideration of the basis set and symmetry constraints in DFT calculations is crucial for determining the critical electric field (E_c), defined as the electric field intensity at which the topological phase transition occurs. Using the ballistic Landauer-Büttiker formula and local potential profile, the drain current-gate bias voltage (I_D-V_G) characteristics were obtained and switching behavior was studied. A comparison with the k·p model reveals the necessity of DFT calculations for investigating realistic edge dispersions. Our approach provides an efficient and rigorous simulation methodology for mesoscopic transport in 2D TIFETs.