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

TL;DR

This paper introduces a first-principles simulation framework for modeling electrostatics and transport in 2D topological insulator transistors, emphasizing the importance of DFT calculations for accurate edge and phase transition analysis.

Contribution

It presents a novel, first-principles based simulation method for 2D topological insulator transistors, integrating DFT with transport calculations for realistic device analysis.

Findings

Critical electric field for topological phase transition depends on basis set and symmetry in DFT.

DFT-based models are necessary for accurate edge dispersion and device behavior.

The framework efficiently combines DFT with Landauer-Büttiker transport calculations.

Abstract

We develop a simulation framework for electrostatic and transport modeling of 2D Topological insulator field-effect transistor (2D TIFETs), based solely on first-principles calculations using density functional theory (DFT). We find that careful consideration of basis set and symmetry constraints in DFT calculations is crucial for determining critical electric field ($E_c$), defined as the electric field intensity at which the topological phase transition occurs. Using ballistic Landauer-B$\"u$ttiker 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 $\mathbf{k}\cdot\mathbf{p}$ 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.