A Tight Binding Approach to Strain and Curvature in Monolayer Transition-Metal Dichalcogenides

Abstract

We present a model of the electronic properties of monolayer transition-metal dichalcogenides based on a tight binding approach which includes the effects of strain and curvature of the crystal lattice. Mechanical deformations of the lattice offer a powerful route for tuning the electronic structure of the transition-metal dichalcogenides, as changes to bond lengths lead directly to corrections in the electronic Hamiltonian while curvature of the crystal lattice mixes the orbital structure of the electronic Bloch bands. We first present an effective low energy Hamiltonian describing the electronic properties near the K point in the Brillouin zone, then present the corrections to this Hamiltonian due to arbitrary mechanical deformations and curvature in a way which treats both effects on an equal footing. This analysis finds that local area variations of the lattice allow for tuning of the band gap and effective masses, while the application of uniaxial strain decreases the magnitude of the direct band gap at the K point. Additionally, strain induced bond length modifications create a fictitious gauge field with a coupling strength that is smaller than that seen in related materials like graphene. We also find that curvature of the lattice leads to the appearance of both an effective in-plane magnetic field which couples to spin degrees of freedom and a Rashba-like spin-orbit coupling due to broken mirror inversion symmetry.

16 pages, 2 figures, revised version v2

References in corpus (11)

• Elastic properties of freely suspended MoS2 nanosheets
• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• Spin-orbit coupling in curved graphene, fullerenes, nanotubes, and nanotube caps
• Magnetic Control of Valley Pseudospin in Monolayer WSe2
• Valley Zeeman Effect in Elementary Optical Excitations of a Monolayer WSe2
• Breaking of valley degeneracy by magnetic field in monolayer MoSe2
• Electron scattering on microscopic corrugations in graphene
• \textit{Ab-initio} Tight-Binding Hamiltonian for Transition Metal Dichalcogenides
• Theory of strain in single-layer transition metal dichalcogenides
• A tight-binding model for MoS${}_2$ monolayers
• Spin-valley relaxation and quantum transport regimes in two-dimensional transition metal dichalcogenides

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