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Proper definition of spin current in spin-orbit coupled systems
Junren Shi1, Ping Zhang, Di Xiao
1Institute of Physics and ICQS, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
Physical Review Letters
|April 12, 2006
Summary
A new definition of spin current is proposed, addressing limitations in describing spin transport with spin-orbit coupling. This measurable spin current aligns with transport theory and vanishes in insulators, with experimental implications discussed.
Area of Science:
- Condensed Matter Physics
- Quantum Mechanics
- Materials Science
Background:
- Conventional spin current definitions are inadequate for systems with spin-orbit coupling.
- Existing models fail to accurately describe spin transport phenomena in certain materials.
Purpose of the Study:
- To establish a complete and physically accurate definition of spin current.
- To develop a measurable quantity for spin current that integrates with existing transport theories.
- To address the limitations of current spin current definitions in the context of spin-orbit coupling.
Main Methods:
- Theoretical framework development based on near-equilibrium transport theory.
- Mathematical formulation of a new spin current definition.
- Analysis of the behavior of the proposed spin current in insulators.
Main Results:
- A revised, physically sound definition of spin current is established.
- The new spin current definition is compatible with near-equilibrium transport theory.
- The proposed spin current correctly vanishes in insulators with localized orbitals.
Conclusions:
- The developed spin current definition offers a more accurate description of spin transport, particularly in systems with spin-orbit coupling.
- This work provides a foundation for future experimental verification and applications.
- The findings contribute to a deeper understanding of fundamental spin-related phenomena in condensed matter systems.
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