Ab initio electronic structure and optical conductivity of bismuth tellurohalides

TL;DR

This study uses ab initio density functional theory to analyze the electronic structure and optical properties of bismuth tellurohalides, providing insights into their potential for spintronics applications.

Contribution

It presents the first comprehensive ab initio calculations of conductivities and dielectric tensors for BiTeX compounds, comparing results with recent experimental data.

Findings

Identification of intra- and interband transitions via low-frequency optical conductivity

Calculated refractive indices and dielectric constants aligned with experimental measurements

Systematic comparison of theoretical predictions with previous studies

Abstract

We investigate the electronic structure, dielectric and optical properties of bismuth tellurohalides BiTeX (X = I, Cl, Br) by means of all-electron density functional theory. In particular, we present the ab initio conductivities and dielectric tensors calculated over a wide frequency range, and compare our results with the recent measurements by Akrap et al. , Makhnev et al. , and Rusinov et al. . We show how the low-frequency branch of the optical conductivity can be used to identify characteristic intra- and interband transitions between the Rashba spin-split bands in all three bismuth tellurohalides. We further calculate the refractive indices and dielectric constants, which in turn are systematically compared to previous predictions and measurements. We expect that our quantitative analysis will contribute to the general assessment of bulk Rashba materials for their potential use in spintronics devices.