Fermi Surface Reconstruction in CeTe2 Induced by Charge Density Wave: ARPES Study

TL;DR

This study uses ARPES to investigate the electronic structure of CeTe_2-xSb_x, revealing Fermi surface features consistent with calculations and identifying FS nesting as the origin of charge density wave formation.

Contribution

It provides direct experimental evidence linking Fermi surface nesting to CDW formation in CeTe_2, with detailed ARPES analysis showing minimal Ce 4f involvement.

Findings

Fermi surface matches calculated undistorted CeTe_2

Carriers near E_F are mainly Te(1) 5p states

FS nesting drives CDW formation along Gamma-X

Abstract

Electronic structures of a charge-density-wave CDW system CeTe_2-xSb_x (x=0, 0.05) have been investigated by employing angle-resolved photoemission spectroscopy (ARPES). The observed Fermi surface (FS) agrees very well with the calculated FS for the undistorted CeTe_2 both in shapes and sizes. The metallic states crossing the Fermi level(E_F) are observed in ARPES. The carriers near E_F have mainly the Te(1) 5p character, with the negligible contribution from Ce 4f states to the CDW formation. The supercell (shadow) bands and the corresponding very weak FS's are found to arise from band-folding due to the interaction with Ce-Te(2) layers. This work shows that the origin of the CDW formation in CeTe_2 is the FS nesting and that the CDW modulation vector is along Gamma-X (Q_CDW ~ X)