Inherent orbital spin textures in Rashba effect and their implications in spin-orbitronics

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• The Rashba effect is known for generating chiral spin textures.
• Orbital angular momentum (OAM) texture underlies Rashba spin texture.
• Understanding spin texture is crucial for spintronics.

Purpose of the Study:

• To investigate the existence and nature of orbital projection (OP) of spin texture in general Rashba systems.
• To analyze the relationship between OP, OAM, and spin texture.
• To explore the influence of crystal field, spin-orbit coupling (SOC), and inversion symmetry breaking (ISB) on these textures.

Main Methods:

• Solving a model Hamiltonian for a generic p-orbital system.
• Analytical derivation of spin polarization dependence on system parameters.
• Comparison with numerical solutions and ab initio calculations.

Main Results:

• Demonstrated the existence of orbital projection (OP) of spin texture in general Rashba systems.
• Showcased that the OP pattern's chirality arises from the same conditions as spin texture chirality.
• Obtained consistent spin polarization results across analytical, numerical, and ab initio methods.

Conclusions:

• The study elucidates the multi-orbital nature of the Rashba effect and its associated OP of spin texture.
• Results suggest potential for external modulation of these spin textures.
• Findings have implications for spin-orbitronics, particularly in controlling orbital occupancy and spin momentum.