Effective tight-binding model for transition metal dichalcogenides
何彥宏1*, Miguel A. Cazallila1
1Physics, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:Yen-Hung Ho, email:yenhungho@gmail.com
By preforming a canonical transformation on the full-band Hamiltonian, we obtain minimum-band models for transition metal dichalcogenides. For the full-band parameters used, we found that starting from Wannier function basis set leads to a better result than from Slater-Koster basis set. Depending on the form of transformation, novel subband features in both the Γ and K valleys are well captured, including the frequency and band effective mass. A close inspection of the transformation projection also enables us to extract the modification on the site energy, as well as the orbital hopping between several nearest neighboring atoms. Instead of pure empirical fitting, our effective models preserve rich orbital physics inside, which is shown to be versatile in studying a variety of fundamental physical properties.

Keywords: transition metal dichalcogenides, tight-binding model