Exploring the Charge Density Wave Phase of 1T-TaSe_{2}: Mott or Charge-Transfer Gap?
Journal
Physical review letters
ISSN: 1079-7114
Titre abrégé: Phys Rev Lett
Pays: United States
ID NLM: 0401141
Informations de publication
Date de publication:
14 Apr 2023
14 Apr 2023
Historique:
received:
10
10
2022
revised:
29
12
2022
accepted:
02
03
2023
medline:
28
4
2023
pubmed:
28
4
2023
entrez:
28
4
2023
Statut:
ppublish
Résumé
1T-TaSe_{2} is widely believed to host a Mott metal-insulator transition in the charge density wave (CDW) phase according to the spectroscopic observation of a band gap that extends across all momentum space. Previous investigations inferred that the occurrence of the Mott phase is limited to the surface only of bulk specimens, but recent analysis on thin samples revealed that the Mott-like behavior, observed in the monolayer, is rapidly suppressed with increasing thickness. Here, we report combined time- and angle-resolved photoemission spectroscopy and theoretical investigations of the electronic structure of 1T-TaSe_{2}. Our experimental results confirm the existence of a state above E_{F}, previously ascribed to the upper Hubbard band, and an overall band gap of ∼0.7 eV at Γ[over ¯]. However, supported by density functional theory calculations, we demonstrate that the origin of this state and the gap rests on band structure modifications induced by the CDW phase alone, without the need for Mott correlation effects.
Identifiants
pubmed: 37115877
doi: 10.1103/PhysRevLett.130.156401
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM