Intrinsic Spin and Orbital Hall Effects from Orbital Texture

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• The spin Hall effect (SHE) and orbital Hall effect (OHE) are crucial phenomena in spintronics.
• Understanding their origins in various material systems is key to developing new electronic devices.
• Centrosymmetric systems, common in materials science, have unique electronic properties.

Purpose of the Study:

• To theoretically investigate the emergence of intrinsic SHE and OHE in centrosymmetric systems.
• To explore the role of momentum-space orbital texture in driving these effects.
• To identify mechanisms for enhancing the spin Hall conductivity in materials.

Main Methods:

• Theoretical modeling of electron transport in centrosymmetric systems.
• Analysis of momentum-space orbital texture and its influence on spin and orbital currents.
• Investigation of the role of spin-orbit coupling (SOC) in converting OHE to SHE.

Main Results:

• Both intrinsic SHE and OHE can arise from momentum-space orbital texture in centrosymmetric systems.
• OHE occurs even without spin-orbit coupling and is converted to SHE via SOC.
• The resulting spin Hall conductivity is significant, comparable to platinum, and exhibits non-monotonic dependence on SOC strength.
• The mechanism is robust against orbital quenching.

Conclusions:

• Momentum-space orbital texture provides a novel route to intrinsic SHE and OHE in centrosymmetric materials.
• This finding suggests new strategies for designing materials with enhanced spin Hall conductivity.
• Experimental validation is encouraged to probe orbital degrees of freedom in OHE and SHE.