Probing intraband excitations in ZrTe$_5$: a high-pressure infrared and transport study

TL;DR

This study investigates how hydrostatic pressure affects the electronic and optical properties of ZrTe$_5$, revealing pressure-induced changes in band parameters and anisotropic conductivity through combined transport and infrared measurements.

Contribution

It provides new insights into the pressure-dependent electronic structure of ZrTe$_5$ using combined high-pressure transport and optical techniques.

Findings

Pressure modifies the Fermi level and effective mass in ZrTe$_5$.

Infrared and transport data support a two-band model with Dirac-like and parabolic dispersions.

Anisotropic conductivity varies with pressure, indicating band structure evolution.

Abstract

Zirconium pentatetelluride, ZrTe5, shows remarkable sensitivity to hydrostatic pressure. In this work we address the high-pressure transport and optical properties of this compound, on samples grown by flux and charge vapor transport. The high-pressure resistivity is measured up to 2 GPa, and the infrared transmission up to 9 GPa. The dc conductivity anisotropy is determined using a microstructured sample. Together, the transport and optical measurements allow us to discern band parameters with and without the hydrostatic pressure, in particular the Fermi level, and the effective mass in the less conducting, out-of-plane direction. The results are interpreted within a simple two-band model characterized by a Dirac-like, linear in-plane band dispersion, and a parabolic out-of-plane dispersion.