First-Principles Simulation and Materials Screening for Spin-Orbit Torque in 2D van der Waals Heterostructures

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Spin-orbit torque (SOT) in two-dimensional van der Waals (2D vdW) materials is advancing spintronic devices to atomic scales.
• Unconventional torques and novel spin-switching mechanisms are being discovered in these materials.
• A systematic strategy is needed to identify optimal 2D vdW materials for high SOT device performance.

Purpose of the Study:

• To establish a screening strategy for identifying optimal 2D vdW materials for SOT applications.
• To discover new high SOT 2D vdW heterostructures.
• To propose a figure of merit for efficient SOT material estimation.

Main Methods:

• Utilized a combination of density functional theory (DFT) and non-equilibrium Green's function (NEGF).
• Calculated SOT in various 2D vdW bilayer heterostructures.
• Developed a figure of merit for rapid SOT estimation.

Main Results:

• Identified three high SOT systems: WTe₂/CrSe₂, MoTe₂/VS₂, and NbSe₂/CrSe₂.
• Proposed a novel figure of merit for efficient SOT estimation.
• Demonstrated the potential for high-throughput screening of SOT materials.

Conclusions:

• The developed DFT+NEGF approach and figure of merit enable efficient screening of 2D vdW materials for SOT applications.
• The identified heterostructures show promise for next-generation spintronic devices.
• This work lays the foundation for accelerated discovery of materials for advanced SOT technologies.