A novel mechanism of charge density wave in a transition metal dichalcogenide

TL;DR

This paper reports a newly discovered charge density wave mechanism in a transition metal dichalcogenide, characterized by partial gap opening and unconventional Fermi surface participation due to strong electronic coupling.

Contribution

It introduces a novel CDW mechanism in a 2H-structured transition metal dichalcogenide, differing from traditional Fermi surface nesting models.

Findings

CDW gap is only partially open

Charge density wavevector involves large Fermi patch states

Straight Fermi surface sections contribute minimally

Abstract

Charge density wave, or CDW, is usually associated with Fermi surfaces nesting. We here report a new CDW mechanism discovered in a 2H-structured transition metal dichalcogenide, where the two essential ingredients of CDW are realized in very anomalous ways due to the strong-coupling nature of the electronic structure. Namely, the CDW gap is only partially open, and charge density wavevector match is fulfilled through participation of states of the large Fermi patch, while the straight FS sections have secondary or negligible contributions.