Modulation of electronic properties from stacking orders and spin-orbit coupling for 3R-type MoS2

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• Two-dimensional van der Waals crystals exhibit unique phenomena.
• Transitional metal dichalcogenides show fascinating properties modulated by symmetry, stacking, and spin-orbit coupling.

Purpose of the Study:

• To investigate the effect of stacking orders and spin-orbit coupling on the electronic properties of few-layer 3R-type MoS2.
• To analyze band splitting and its relation to stacking sequences.

Main Methods:

• First-principles calculations.
• Analysis of valence and conduction band states.
• Model Hamiltonian for layer coupling.

Main Results:

• Stacking order and spin-orbit coupling influence electronic band splitting in few-layer MoS2.
• Spin-up and spin-down channels are separated, forming a basis for valley-dependent spin polarization.
• Stronger nearest-neighbor coupling observed for abc and abca stacking sequences.

Conclusions:

• Stacking sequences significantly affect electronic properties and spin polarization in MoS2.
• The findings suggest the prevalence of periodic abc stacking in natural MoS2 growth.
• Understanding these effects is key for designing novel spintronic and valleytronic devices.