Prediction of Anisotropic Single-Dirac-Cones in Bi${}_{1-x}$Sb${}_{x}$ Thin Films

TL;DR

This paper presents a method to predict and construct anisotropic single-Dirac-cones in Bi${}_{1-x}$Sb${}_{x}$ thin films, enabling tailored electronic properties for various applications.

Contribution

We developed an iterative two-dimensional two-band model to accurately predict anisotropic Dirac cones in Bi${}_{1-x}$Sb${}_{x}$ thin films, considering non-parabolic dispersion relations.

Findings

Able to predict anisotropic Dirac cones in thin films.

Model accounts for non-parabolic dispersion relations.

Provides a basis for engineering electronic properties.

Abstract

The electronic band structures of Bi${}_{1-x}$Sb${}_{x}$ thin films can be varied as a function of temperature, pressure, stoichiometry, film thickness and growth orientation. We here show how different anisotropic single-Dirac-cones can be constructed in a Bi${}_{1-x}$Sb${}_{x}$ thin film for different applications or research purposes. For predicting anisotropic single-Dirac-cones, we have developed an iterative-two-dimensional-two-band model to get a consistent inverse-effective-mass-tensor and band-gap, which can be used in a general two-dimensional system that has a non-parabolic dispersion relation as in a Bi${}_{1-x}$Sb${}_{x}$ thin film system.