Effective lattice Hamiltonian for monolayer tin disulphide: tailoring electronic structure with electric and magnetic fields

TL;DR

This paper develops an effective lattice Hamiltonian for monolayer tin disulphide, enabling accurate modeling of its electronic structure and responses to electric and magnetic fields, facilitating future research and device design.

Contribution

The paper introduces a new tight-binding model based on six hybrid orbitals that accurately reproduces the electronic properties of ML-SnS2 and can incorporate external electric and magnetic fields.

Findings

Good agreement with density functional theory calculations.

Model captures Landau levels under magnetic fields.

Electric field effects are effectively modeled.

Abstract

The electronic properties of monolayer tin dulsulphide (ML-SnS2), a recently synthesized metal dichalcogenide, are studied by a combination of first-principles calculations and tight-binding (TB) approximation. An effective lattice Hamiltonian based on six hybrid sp-like orbitals with trigonal rotation symmetry are proposed to calculate the band structure and density of states for ML-SnS2, which demonstrates good quantitative agreement with relativistic density functional theory calculations in a wide energy range. We show that the proposed TB model can be easily applied to the case of an external electric field, yielding results consistent with those obtained from full Hamiltonian results. In the presence of a perpendicular magnetic field, highly degenerate equidistant Landau levels are obtained, showing typical two-dimensional electron gas behavior. Thus, the proposed TB model provides a simple new way in describing novel properties in ML-SnS2.