Electronic band structure calculations for monolayer NbSe2 using tight-binding analysis

Abstract

We present a tight-binding (TB) model to calculate the electronic band structure of monolayer 2H-NbSe₂. Here, the Bloch state wavefunctions derived from first principles calculations based on density functional theory (DFT) were transformed to a set of maximally-localized Wannier functions projected on the prominent orbitals around the Fermi energy level. The tight-binding parameters were extracted from the obtained Hamiltonian in Wannier basis. This allows us to generate the tight-binding electronic band structures up to various levels of nearest neighbors (i.e., first, second, or third nearest-neighbors) specified by a Hamiltonian cut-off radius r_h. The results show that with increased r_h, the TB band structure fits more accurately with the band structure calculated from first principles DFT.