Pressure dependence of the charge-density-wave gap in rare-earth tri-tellurides

TL;DR

This study examines how applying pressure affects the charge-density-wave gap in CeTe$_3$, revealing that increased pressure reduces the gap and alters electronic properties by disrupting Fermi surface nesting.

Contribution

It provides the first detailed analysis of pressure effects on the CDW gap in rare-earth tri-tellurides using optical spectroscopy.

Findings

CDW gap decreases with pressure

Pressure broadens electronic bands and reduces nesting

Electronic properties are altered by lattice compression

Abstract

We investigate the pressure dependence of the optical properties of CeTe$_3$, which exhibits an incommensurate charge-density-wave (CDW) state already at 300 K. Our data are collected in the mid-infrared spectral range at room temperature and at pressures between 0 and 9 GPa. The energy for the single particle excitation across the CDW gap decreases upon increasing the applied pressure, similarly to the chemical pressure by rare-earth substitution. The broadening of the bands upon lattice compression removes the perfect nesting condition of the Fermi surface and therefore diminishes the impact of the CDW transition on the electronic properties of $R$Te$_3$.