Huge Rashba-type spin-orbit coupling in binary hexagonal PX nanosheets (X = As, Sb, and Bi)

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Two-dimensional (2D) materials offer unique electronic properties.
• Spin-orbit coupling (SOC) is crucial for spintronics.
• Rashba-type SOC arises from broken inversion symmetry.

Purpose of the Study:

• To theoretically investigate Rashba-type spin-orbit coupling in binary alloyed hexagonal PX nanosheets (X = As, Sb, Bi).
• To explore the tunability of SOC strength via strain engineering.

Main Methods:

• First-principles calculations.
• Density Functional Theory (DFT).
• Analysis of electronic band structure and spin properties.

Main Results:

• Rashba-type band splitting predicted in PX nanosheets due to broken inversion symmetry.
• PBi exhibits the largest band splitting with a Rashba coefficient of ~1.56 eV Å.
• Tensile biaxial strain significantly enhances SOC, reaching 4.41 eV Å at 10% strain.

Conclusions:

• PX nanosheets, especially PBi, are promising candidates for spintronic devices.
• Strain engineering offers a powerful method to tune Rashba-type SOC in these materials.