Quantum Kinetic Anatomy of Electron Angular Momenta Edge Accumulation

Area of Science:

• Condensed Matter Physics
• Spintronics
• Quantum Materials

Background:

• Controlling electron spin and orbital degrees of freedom is crucial for electrical manipulation of magnetization.
• Recent advances in quantum kinetic theory for multiband systems provide new analytical tools.

Purpose of the Study:

• To partition the intrinsic angular momenta linear response into intra- and interband contributions.
• To investigate the origin of spin and orbital Hall currents and edge densities in symmetric metals.
• To explore the implications for interpreting orbital edge accumulation and current-induced torques.

Main Methods:

• Application of a quantum kinetic theory for multiband systems.
• Analysis of linear response for intrinsic angular momenta.
• Focus on time-reversal and inversion symmetric metals.

Main Results:

• Spin and orbital Hall currents are found to be purely intraband.
• Intrinsic edge densities have a partial, and possibly dominant, interband contribution, especially for orbital effects.
• A novel interband mechanism for orbital edge accumulation is identified.

Conclusions:

• The findings necessitate a re-evaluation of orbital edge accumulation observations.
• The identified interband mechanism has significant implications for understanding and engineering current-induced torques.
• This work advances the theoretical framework for spintronic phenomena in multiband systems.