Fermi Surface reconstruction in the CDW state of CeTe3 observed by photoemission

TL;DR

This study uses angle-resolved photoemission to observe Fermi surface reconstruction in CeTe3 caused by charge density wave formation, revealing FS pockets and the role of nesting, which had been difficult to detect before.

Contribution

It provides direct experimental evidence of Fermi surface pockets formed by CDW-induced backfolding in CeTe3, clarifying the role of nesting in CDW formation.

Findings

Identification of backfolded bands and FS pockets

Observation of partial gapping of the Fermi Surface

Explanation of weak folded band intensity

Abstract

CeTe3 is a layered compound where an incommensurate Charge Density Wave (CDW) opens a large gap (400 meV) in optimally nested regions of the Fermi Surface (FS), whereas other sections with poorer nesting remain ungapped. Through Angle-Resolved Photoemission, we identify bands backfolded according to the CDW periodicity. They define FS pockets formed by the intersection of the original FS and its CDW replica. Such pockets illustrate very directly the role of nesting in the CDW formation but they could not be detected so far in a CDW system. We address the reasons for the weak intensity of the folded bands, by comparing different foldings coexisting in CeTe3.