Multiband [formula omitted] model for Monalayer Sn[formula omitted](X=S,Se)

Abstract

Multiband k⋅p models have been constructed for the monolayer SnX2(X=S,Se) based on the symmetry consideration alone. Two conductance and ten valence bands are included capable of describing the energy band dispersion, spin–orbit coupling, and strain effect, in good agreement with the first-principle results. Spin–orbit coupling strength has been confirmed. Interestingly, the valence bands show enormous change even when applying small strain due to the competition between the valence bands. SnX2 are typical transition-metal dichalcogenides compounds which have drawn extensive attention for decades, our k⋅p theory provides a simple and convenient way to understand and manipulate the optical and transport properties of these materials and their nanostructures by strain and external fields.