$Bi_2Te_3$: Implications of the rhombohedral k-space texture on the evaluation of the in-plane/out-of-plane conductivity anisotropy

TL;DR

This paper compares computational methods for surface integrals in anisotropic Brillouin zones, focusing on Bi2Te3's transport properties, highlighting the importance of reciprocal space integration to accurately evaluate in-plane and out-of-plane conductivity anisotropy.

Contribution

It demonstrates the necessity of thorough reciprocal space integration to accurately assess anisotropic transport properties in layered materials like Bi2Te3.

Findings

Strong anisotropy in transport distribution function due to layered structure and symmetry.

Quantitative comparison of anisotropic mass tensor at band edges.

Reciprocal space integration is crucial for accurate anisotropy evaluation.

Abstract

Different computational scheme for calculating surface integrals in anisotropic Brillouin zones are compared. The example of the transport distribution function (plasma frequency) of the thermoelectric Material \BiTe near the band edges will be discussed. The layered structure of the material together with the rhombohedral symmetry causes a strong anisotropy of the transport distribution function for the directions in the basal (in-plane) and perpendicular to the basal plane (out-of-plane). It is shown that a thorough reciprocal space integration is necessary to reproduce the in-plane/out-of-plane anisotropy. A quantitative comparison can be made at the band edges, where the transport anisotropy is given in terms of the anisotropic mass tensor.