Strain effects on the spin-orbit induced band structure splittings in monolayer MoS2 and graphene

TL;DR

This paper investigates how different types of strain influence the spin-orbit induced band structure splittings in monolayer MoS2 and graphene, using first-principles calculations and effective Hamiltonian modeling.

Contribution

It introduces a detailed theoretical framework linking strain symmetry to band splittings and extracts relevant parameters through first-principles fitting.

Findings

Splittings depend on strain symmetry types.

Effective Hamiltonian accurately models strain effects.

Results relate band splittings to electron-phonon interactions.

Abstract

The strain effects on the spin-orbit induced splitting of the valence band maximum and conduction band minimum in monolayer MoS2 and the gap in graphene are calculated using first-principles calculations. The dependence of these splittings on the various symmetry types of strain is described by means of an effective Hamiltonian based on the method of invariants and the parameters in the model are extracted by fitting to the theory. These splittings are related to acoustic phonon deformation potentials, or electron-phonon coupling matrix elements which enter the spin-dependent scattering theory of conduction in these materials.