NATURE OF CHARGE DENSITY WAVES IN GROUP-VB TRANSITION METAL DICHALCOGENIDES

Abstract

In this thesis, we have performed comprehensive ab-initio studies of the charge density wave (CDW) properties of monolayer 1T-VSe2, 1H-NbSe2, and 1T-VTe2. The calculations have been established in the scheme of density functional perturbation theory, and with the help of mean-field theory to elucidate the underlying physics of the charge density waves. Both phonon softening and CDW gap opening have been carefully checked. Moreover, the interplay between CDW and other quantum orders is also studied.