Disentangling edge and bulk spin-to-charge interconversion in MoS₂ monolayer flakes

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Semiconductor transition metal dichalcogenides exhibit spin-to-charge interconversion, crucial for spintronics.
• The microscopic origins of this interconversion in materials like MoS2 are not fully understood.

Purpose of the Study:

• Investigate light-induced spin pumping in Yttrium Iron Garnet/Molybdenum Disulfide (YIG/MoS2) heterostructures.
• Determine the mechanisms responsible for spin current injection in MoS2 flakes.
• Explore the influence of flake size and light on spin-pumping behavior.

Main Methods:

• Experimental investigation of light-induced spin pumping in YIG/MoS2 heterostructures.
• Density Functional Theory (DFT) calculations to determine the local density of states.
• Analysis of spin current injection through metallic edge states and semiconductor area states.

Main Results:

• MoS2 monolayer flakes contribute to spin current injection via both metallic edge states and semiconductor area states.
• Flake size influences the competition between these mechanisms, altering spin-pumping behavior.
• Light-driven spin current injection can be controlled by light intensity and wavelength, enabling enhancement, attenuation, or switching of spin-to-charge interconversion.

Conclusions:

• The study elucidates the dual mechanisms of spin current injection in MoS2 flakes.
• Controllable opto-spintronic behavior is demonstrated through light manipulation.
• Findings pave the way for developing energy-efficient opto-spintronic devices.