Temperature Dependence of Optical Spectra for the CDW Gap and Optical Phonons in BaBiO_3

TL;DR

This study investigates how the optical spectra related to the charge density wave gap and phonons in BaBiO_3 change with temperature, revealing that phonon conductivity decreases with temperature while the CDW gap remains stable.

Contribution

It provides new insights into the temperature dependence of optical properties in BaBiO_3, especially distinguishing behaviors of phonons and CDW gap excitations.

Findings

Optical phonon conductivity decreases rapidly above 150 K.

CDW gap excitation remains constant across the temperature range.

Single crystal and film samples show similar temperature dependence.

Abstract

We have studied the temperature dependence of the optical spectra for the CDW gap and optical phonons in a single crystal of BaBiO_3 and a film deposited by laser ablation. The integrated optical conductivity for optical phonons decreases rapidly with increasing temperature above 150 K, while the single-particle excitation across the CDW gap remains constant.