Chemical pressure and hidden one-dimensional behavior in rare earth tri-telluride charge density wave compounds

TL;DR

This study presents optical measurements of rare-earth tri-telluride compounds, revealing a possible one-dimensional behavior and the influence of chemical pressure on charge-density-wave properties across the series.

Contribution

First optical analysis of rare-earth tri-tellurides showing the evolution of charge-density-wave features with lattice constant, suggesting one-dimensional characteristics.

Findings

Charge-density-wave impact diminishes with decreasing lattice constant.

Evidence of one-dimensional behavior in these two-dimensional compounds.

Interactions and umklapp processes may influence CDW formation.

Abstract

We report on the first optical measurements of the rare-earth tri-telluride charge-density-wave systems. Our data, collected over an extremely broad spectral range, allow us to observe both the Drude component and the single-particle peak, ascribed to the contributions due to the free charge carriers and to the charge-density-wave gap excitation, respectively. The data analysis displays a diminishing impact of the charge-density-wave condensate on the electronic properties with decreasing lattice constant across the rare-earth series. We propose a possible mechanism describing this behavior and we suggest the presence of a one-dimensional character in these two-dimensional compounds. We also envisage that interactions and umklapp processes might play a relevant role in the formation of the charge-density-wave state in these compounds.