Charge density wave modulation and gap measurements in CeTe$_3$

TL;DR

This study investigates charge density wave ordering in CeTe$_3$ using STM and Raman spectroscopy, identifying characteristic wavevectors and a CDW gap of about 0.37 eV, along with atomic organization patterns.

Contribution

It provides detailed measurements of CDW wavevectors and gap in CeTe$_3$, combining STM and Raman spectroscopy for comprehensive analysis.

Findings

CDW wavevectors identified as 4.19 nm$^{-1}$ and 10.26 nm$^{-1}$

CDW gap measured at approximately 0.37 eV

Observation of atomic organization in Te sheets consistent with theoretical predictions

Abstract

We present a study of charge density wave (CDW) ordering in CeTe$_3$ at room temperature using a scanning tunneling microscope and Raman spectroscopy. Two characteristic CDW ordering wavevectors obtained from the Fourier analysis are assessed to be $|{\bf \textbf{c}}^\ast-{\bf q}|=4.19\,{\rm nm}^{-1}$ and $|{\bf q}|=10.26\,{\rm nm}^{-1}$ where $|{\bf c}^\ast| = 2\pi/c$ is the reciprocal lattice vector. The scanning tunneling spectroscopy measurements, along with inelastic light (Raman) scattering measurements, show a CDW gap $\Delta_{\rm max}$ of approximately 0.37 eV. In addition to the CDW modulation, we observe an organization of the Te sheet atoms in an array of alternating V- and N- groups along the CDW modulation, as predicted in the literature.