Optical conductivity of layered topological semimetal TaNiTe$_5$

TL;DR

This study investigates the optical properties of TaNiTe$_5$, revealing it as a three-dimensional anisotropic semimetal with conventional metallic behavior despite its layered structure.

Contribution

The paper provides the first comprehensive optical and transport characterization of TaNiTe$_5$, confirming its three-dimensional electronic structure through experimental and theoretical analysis.

Findings

Optical conductivity shows anisotropic but conventional metallic response.

Infrared reflectivity indicates metallic behavior along both axes.

Ab initio calculations match experimental data, confirming 3D electronic structure.

Abstract

We present an infrared spectroscopy study of the layered topological semimetal TaNiTe$_5$, a material with a quasi-one-dimensional structure and strong in-plane anisotropy. Despite its structural features, infrared reflectivity and electronic transport measurements along the $a$ and $c$ crystallographic axes show metallic behavior without evidence of reduced dimensionality. Optical conductivity reveals an anisotropic but conventional metallic response with low scattering rates and a single sharp infrared-active phonon mode at $396$ cm$^{-1}$ ($49$ meV). Ab initio calculations closely match the experimental optical data and confirm a three-dimensional electronic structure. Our results demonstrate that TaNiTe$_5$ behaves as a three-dimensional anisotropic semimetal in its electronic and optical properties.